There was a HUGE amount of only-vaguely repressed sexual exploitation in Silver Age comics, especially involving violence towards women and especially involving the buttocks, and so it's likely to do with that. Despite the fact it was marketed to 4-6 year old kids, almost every story in Lois Lane's comic (for example) involved some kind of sexual deviancy or another. Really the spanking was the least offensive aspect of the whole generation.
Didn't the spankings mostly happen in the Golden Age?
How come most silver age comics tended to have it with the characters or narrator explaining everything we can quite clearly see for ourselves by looking at the art in the very panel?
Erm, not quite. In reality it's because during the Silver Age it was assumed only young children read comics. So really it's like that for the same reason a Berenstein Bears book will have the narration explaining everything you can clearly see happening in the pictures.
Also, the way those stories were usually written, the entire script was written before the art was drawn, and there wouldn't be time to make script edits after the art came in. If the artist's storytelling was vague or unclear, tough luck, there's little time to add in some explanatory dialogue. So add in the explanatory dialogue beforehand, because you never know when the artist will have an off moment and make it look like Hero X is doing the jitterbug when he's supposed to unleashing a ninja kick.
What's with all the lingering nostalgia? People who work in the comic industry keep trying to reach back to it, even parts that were really stupid. Don't get me wrong, the Modern Age has its fair share of stupid, stupid moments, but some people, like Alex Ross, seem to think the Silver Age was the era of "Greatest comics ever." And sometimes the reversions to the Silver Age work out nicely, other times they blow up in someone's face.
I think it's more the themes of the Silver Age that people are trying to hearken back to, not the insane/stupid moments. There's something to be said for the pure, unambiguous heroes and villains of the Silver Age. After so many years of moral grey areas, grim&gritty anti-heroes, and sympathetic villains, a lot of people have been yearning for a return to the good-ol-days when heroes were unambiguously good and villains were Always Chaotic Evil.
What's slightly annoying about this nostalgic viewpoint is that the best silver age creators weren't the guys just repeating the last generation's efforts but also experimenting and bringing new ideas to the medium, Like Lee, Kirby and Steranko.
Few if any creators yearn for the actual writing style the Silver Age. It's specific characters and concepts that they try to bring back, not the style of writing.
It's not about actually wanting to bring back the Silver Age so much as it's a deliberate reaction against the Dark Age, which kept comics mired in a stew of pointless grimdark for far too long, and was in large part an attempt to distance comics as a medium from the silliness and fun of the Silver Age.
I consider it a giant case of "failure to launch." The Dark Age of Comics was like an unsightly adolescence that comics first had to go through to break out of its aesthetic childhood. It was often unappealing—kind of like a teenager's cheesy first attempt at a mustache. But it seemed that once comics got the ridiculous levels of Grim Dark out of its system, it could maybe try embracing genuinely adult themes and concerns. But on the cusp of adulthood, many of the man-children in charge (and in the audience) decided that a SECOND FREAKING CHILDHOOD was the ticket instead. Aesthetically speaking, they've moved back into mommy's basement.
I personally don't think that comics are reverting back to the Silver Age; I think that recent comics add references to Silver Age occurrences simply to acknowledge that that era still exists and has not been retconned out. The only purpose for this is to establish a straightforward continuity for each comics universe. I find that DC does this more than Marvel because Marvel never retconned out their Silver Age, but DC previously did shortly after Crisis on Infinite Earths. Now, DC has begun to regret that decision.
Brainwashing, of a sort. People who grew up reading those comics were heavily influenced by them, indoctrinated really, into believing that comics should be one way and never change. The Dark Age, as much as people hate it, was an attempt by "outsiders" to break from that. A lot of the hate against the Dark Age is people who were indoctrinated under the "old regime" now pushing back against the new, so you get the Modern Age, an overly ironic attempt at both haranguing the Dark Age and stroking the Silver Age's withered manhood, while confusedly trying to explain the "silly and fun" parts of the Silver Age...things that would never make sense in any kind of story outside of Lolita or a horror-comedy. Also so much time has passed now people forget about the rampant pedophilia, the oversexualization of children, the overt racism, sexism and classism and horrifically flawed morals that drove the Silver Age. Remember this was a time when showing what amounted to a prepubescent boy stroking a lightning bolt between his legs in a manner that suggests nothing else if not a massive penis was considered to be not just commonplace but entirely normal. But few people really remember that, they think it was "silly and fun" not a horrible mishmash of racist diatribes, sexism and pedophila...which it was. So yeah...
Why are people talking as if the Dark Age followed directly from the Silver Age. Are you forgetting there were fifteen years of Bronze Age in between them? Most people who, like me, suffered the excesses of the Dark Age were too young to have read Silver Age comics, we grew reading Bronze Age. Far from my intention to pretend that the Bronze Age was free from stupidity, but it had left behind the Jimmy Olsen type sillines that you seem to think is the only alternative to the Dark Age over-the-top grittiness. Most of us see the worst of the Silver Age as so-bad-is-good, fun to point at it and laugh, but the worst of the Dark Age wasn't even unintentionally funny.
And man... Brainwashing? Indoctrination? Are you sure you aren't taking all this a little too seriously?
Indoctrination is being overly kind, frankly. The level of reinforcement and the childishness on display during the Silver Age is bad enough on its own, but the whole era was so overflowing with misogynistic nonsense it's literally scary. And personally as a Black man I find the idea that the Silver age was anything but disgustingly racist to be worthy of a good chuckle—even a cursory glance at it reveals virtually every Black character as some kind of mindless Golum like monster with the face of a shaved chimp and the cadence of R-Truth minus the "this is obviously a parody, meant to be shocking and offensive" label that R-Truth works under. The influence it had on comics afterwards did far, far more harm than good and the fact people want it back and yet still, as I said, confusedly try to explain it in a way that doesn't embarrass them is quite telling—a whole generation of comic writers couldn't give up their favorite pet, but can't also admit how wildly out of place it is in a world where Nigger isn't casually used in conversation and children sleeping nude with adult men is seen as at the very least "suspicious". For all the criticism the Dark Age gets it had one-tenth of the completely insane violence and vitriol against minorities and women that any random Silver Age Superman comic has and that's before you take into account the fact they were never marketed to children in such a state. If all the Silver Age was was just Jimmy Olsen turning into a Gamera every few issues then it wouldn't be a problem. The problem was the childishness of it all is wrapped in a terrifying 80-hit Ultra Combo of badness and hate speech that makes the average Chick Tract look like an editorial from The Nation.
And far be for me to say the ONLY alternative to the Silver Age is the Dark Age—I make no secret that I'm a huge fan of that era, and yes Rob Liefield too—but there of course of many in-between areas. In point of fact the Bronze Age was a nice middle man, and if I had my way it would be far more fondly remembered. Unfortunately no one wants to "bring back" the Bronze Age, and everytime, say, Justice League Detroit is mentioned it's done so in a manner which makes it sound like Vibe personally killed Jesus by burning Jews on his front lawn alongside Vidkun Quisling. I WISH people wanted to bring Vibe back. Unironically. But no we need to bring back the horrifying, racist, sexist, childlike maelstrom of nuclear chaos that slammed into America like a hurricane and gave us such brilliant stories as "Superman can now launch a miniature version of himself from his fingers for no good reason" and "Batman is turned into a baby yet still as intelligent and strong as a man, because physics" or how about "Lois Lane goes back to in time to a doomed planet just to have sex with Kal-El's father (sweet Jesus!) then leave him to die afterwards". But oh no, Vibe is a breakdancer, so he must die. And Cable has guns he must die too. Yay.