The Aristocats' entire plot hinges on the fact that Edgar apparently believes cats literally have nine lives. There is also that fact that the Disney Encyclopedia writer, John Grant, points out that had Edgar obeyed the wishes of the will, he would have had a guaranteed job taking care of Madame's "heirs" until he almost certainly outlives them (cats in Real Liferarely live more than 12-15 years) and gets the remainder of the inheritance all for himself.
Even worse is his belief that each cat will live for x years times 9 times number of cats. If each cat lives for ten years per life, they will live for ninety years, there are four cats so that would be 360 years... completely ignoring several basic facts (Duchess is older than her kittens and so would live a shorter period after Madame's death, the cats are alive at the same time and not consecutively, cats don't even HAVE nine lives).
Not to mention, the lawyer and Madame are both completely crazy and it probably isn't legal to leave property to cats. It could be left in trust, with Edgar in charge of the actual spending, so there is nothing to stop him living the high-life as long as he keeps buying cat food.
The last third of Gumby: The Movie falls into this. Someone even suggests calling the police after the blockheads have Gumby and the band kidnapped, but the agent says "No time for that". While it thankfully turns out well with the blockheads tied up and the robot substitutes deactivated...They literally just leave the blockheads tied up...in their lab...and within a meter of the controls.
The LEGO Movie has an in-universe example: The popular Show Within a ShowWhere Are My Pants? has exactly one joke: A man can't find his pants. For every episode.When Wyldstyle hijacks the show's set to make a broadcast, she throws a pair of pants at the actor, declaring "Found your pants! The series is over!"
Interestingly, the movie even parodies itself in this regard in an alternate ending. In this ending, Lewis takes Goob along with him in the time machine to the day when Goob fell asleep during his game. Goob shouts at his past self to wake up and his past self does so, then proceeds to catch the ball and win the game. Future Goob then contemplates how this was all he would've had to do all along and all his other plans were unnecessary.
Scooby-Doo and the Cyber Chase is guilty of this. Someone created the virus. No one knows who. They get zapped into their friend's game, which is based on them. Can't they just get pulled back out? Of course not! Turns out the "geniuses" that made the special laser and game didn't think to make an emergency escape program. That's not all. The virus, for some reason, likes to make baseball references, constantly. Does the gang figure out who made the virus straight away? No. They make it to the final level and face off with the virus. The reveal of this "mystery" is that Bill the baseball fan was the one who created the virus. Nice job, gang. That was a tough one.
Though the team do pick up on the baseball references and it's not like they were in a position to tell anyone.
Right after Springfield is sealed in the dome, Professor Frink reveals that he has a laser drill that can break through it, but it's outside the dome. The trapped Springfield residents could have dug a tunnel under the dome, retrieved the drill, and started breaking through. Not a single person in town figured this out, even AFTER the Simpsons escaped the dome via the sinkhole in their back yard.
The residents spend most of the episode oblivious to the possibility that their problems could be solved with an old-fashioned town hole digging (Willie asks himself why he didn't think of that), and it is a guest star (Sting) who is the best digger. Springfieldianites just are not very smart, especially when it comes to digging holes, since moreover in another episode they dig themselves into a hole and their plan for digging their way out is to "Dig up, stupid". The real idiot plot in this movie is Homer dumping waste into the lake after he was warned by his non-idiot daughter that this would be the death of everyone and everything he loved. But then again, it's quite common for Simpsons plots to exist because Homer willingly crippled his IQ with a crayon and did something stupid. Lampshaded in a later episode wherein Mr. Burns decides to cover the town in a dome, only to been told it happened already. Then Carl points out that they could've dug their way out the last time.
Thumbelina does ask the bird to take her home several times. The bird genuinely thinks that it's more important to abandon her in favor of finding Cornelius. Yeah.
We're Back! A Dinosaur's Story: A scientist from the future goes back in time and collects dinosaurs, force evolves their brains so they're just smart enough to be able to speak and reason on a fourth grade level (except poor Dweeb, who's basically left intellectually-impaired), brings them to modern day New York and then just drops them off in the city with very vague instructions of finding a fellow scientist without any training or understanding of how modern life functions. The entire city mistakes them for balloons, until one girl points out they're not, just because they happen to be marching with the Thanksgiving Day parade, never mind the fact that they are dancing and singing. Then a good chunk of the plot revolves around the dinos stumbling into trouble, being chased by the authorities and then trying to rescue two kids who stupidly signed a contract with an obviously creepy old circus owner. The time traveler comes back to save everything, but after all the madness has happened, not before. If anybody in the movie put more than three seconds of thought into their actions, it would be a pretty short story.
The heroes and NPCs of Wreck-It Ralph are well aware that (a) their villains are only doing a job and not actually evil and (b) a main character running out on their game is a very, very bad thing. Doesn't stop them treating their bad guys like dirt and then acting all surprised and dismayed when one of them finally snaps and abandons his game to try and make a better life for himself.
Norm of the North would have been non-existent if the developer didn't try to sell homes in the arctic. Or if Norm, after hearing how the ad campaign is dead unless they find someone who looks just like him, goes with them to stop him! Why is never explained, except with a fight them when their guard is down logic. Somehow NO ONE actually does anything, with Mr Greene being the one with the idiotic schemes, and almost everyone is useless. Early in the movie Mr Greene runs around NYC with a rifle TO SHOOT NORM IN A CROWDED RESTAURANT! Not only should he not have done that, but everyone likes him for it, and it raises his approval ratings. That should've happened at the end where they tricked him, getting him fired. Why did they make him do that? Why would you like someone you didn't like before when they'd gone postal? Why buy a house in the arctic? I don't know. Everything is stupid. Why are the gerbil lemmings the only ones who aren't complete idiots? They can't even speak.