Although Doug Walker may be slightly embarrassed by one of his first works, starring himself as a cowboy, he had the guts to upload it to That Guy with the Glasses.com for all to laugh at. You have to give him credit for that.
The Nostalgia Critic's Let's Play he did of Bart's Nightmare fell under this rather quickly, primarily because a) it was too angrishy and b) he was on holiday and wanted to give the fans something other than commentaries. In the following episode, the Critic ended up going to prison (one symbolically placed right next to a location from the movie he hates more than any other) for making the video and publicly apologized to the masses who wanted his blood.
In his commentary for that very review, Doug said that he picked the very worst movies he made, as a response to people thinking the previous Old Shame childhood movies he showed clips of weren't so bad.
Nella: "Rule Number One! We don't talk about Rape Rap!"
After getting banned from the SCP Foundation, senior member Fishmonger asked the site to remove all of the articles, stories, and materials he had ever written for the site. Barring the obvious reasoning, some site members theorized that Fishmonger was afraid potential employers would stumble across the site.
The first two Chaos Fighters installments are set for rewrite because of this trope, namely being lower quality compared to the rest of the series.
Rocco Botte, while he doesn't completely disown or hate Mega64 Version 1, has shown to be embarrassed and apologetic for a lot of the episodes' shortcomings. This is painfully apparent in the Special Edition Commentary.
Oancitizen of Brows Held High wound up taking down his review of The Girlfriend Experience about a month after it went up on That Guy with the Glasses, citing that he didn't care for some of the implications that he made about adult film stars and decided he didn't want it to represent him as a critic. He uploaded a commentary of the review instead, explaining the reasoning behind this.
The crew at Incognito Cinema Warriors XP stopped selling copies of their first episode, Bride of The Gorilla (and never released it to Rifftrax), citing the low quality relative to subsequent episodes, elements that flat out didn't work (like a jarringly out-of-place Laugh Track) and a lack of interest in redoing the episode to bring it up to par. It's a Lost Episode now and it's staying that way. (You can't even find clips of the thing on YouTube).
As explained in their official history, in aftermath of the dot-com bubble bursting in the early '00s Newgrounds had to resort to running ads for porn sites in order to keep the lights on. They are not proud of this, mainly due to the poor image it gave to the site.