Stupidity: When seeing that the bridge is out, JLC could've easily climbed out of the sunroof and hop off the back of the limo and onto the pavement, suffering a few cuts and bruises at the most. I know that it would've been anticlimactic, but still.
Suggested correction: You're assuming that jumping off a runaway car is a simple task that anyone can do. She's scared out of her mind, and many people in a similar situation would probably be scared at the prospect of jumping off a moving car, even with the knowledge that they will be flying off the road shortly.
Stupidity: Felix and the DEA capture Sanchez, a very powerful drug lord, in a very public way, have the wedding...then everyone just goes home. No concept of extra security or concern about his minions getting revenge. So of course they can then just wander into his house with no problems whatsoever to capture him and murder his wife. Bond's clearly concerned when he learns Sanchez has escaped, but he must have realised there'd be plenty of goons still around before that point.
Stupidity: When Jonathan is chasing the truck to try and save Sarah, he could have removed his heavy backpack and run faster...but instead just leaves it on. No wonder he wasn't fast enough.
Stupidity: The protagonist is wearing normal boots atop a spacesuit while being on a moon mission. (01:37:11)
Stupidity: Right before the movie's final battle, Sub-Zero taunts Cole with his wife's necklace and makes him chase him into a portal. Sonya was right next to Cole, and she did not come along with him. They had previously planned to take on Sub-Zero together, but apparently she just left him to chase Sub-Zero alone to an unknown location.
Stupidity: Jake uses several Loops and travels all over the world in order to get back on the boat at the end of the film. This was completely unnecessary as only the final Loop in 1942, which was available to him in 2016, was the one he needed to enter despite the fact that its nature should have prevented him from reaching 1943 anyway.
Stupidity: Kora and Gunnar arrive at the town to find the rebel Bloodaxes via a contact of Gunnar's. They literally see this contact being hauled out of a bar by bounty hunters who work for the Imperium...and then walk straight into the same bar and start openly talking about needing to find the rebels right in front of the bartender and other patrons, who for all they know are all Imperium-aligned.
Stupidity: Despite being wanted for murder, escaping jail, and having his face plastered on the front page of the newspaper, Morbius meets Martine in a public diner and doesn't even make an attempt to conceal his identity while they are seated. Even shaving off his beard and cutting his hair short would have gone a long way in making him more unrecognizable.
Stupidity: Immediately after Unkar Plutt makes Rey a generous offer for BB-8 and she refuses, he tells someone over his communicator to follow her and bring back the droid. He should have at least waited until she was out of earshot before he said that, especially if he was trying to be covert about it.
Suggested correction: But he was out of earshot of her.
I posted this immediately after watching the scene in question, and it looked as though Plutt spoke into his communicator right after Rey turned around and went on her way; certainly too soon for her to have gotten more than a few steps away. Also, he spoke at a normal, conversational volume rather than anything that sounded like a whisper or "sotto voce", so unless he was relying on the ambient noise of other nearby activity, I still believe this "stupidity" is valid.
That depends on how sneaky you think Plutt is. Rey walks away in quick paces, so she is out of earshot. Also I don't think it bothers him that much if she heard, she is just a scavenger, what can she do about it?
Rey was definitely out of earshot. Rey walks completely out of the shot, which appears to be about 10 feet away. Unkar Plutt then angrily swipes the portions off the counter and picks up his communicator. At the pace Rey was walking she would have been a considerable distance away from him when he spoke. In addition, Unkar Plutt lowered his voice when he spoke because he was being sneaky. She might have been able to hear him speak, but it is totally reasonable that she wouldn't be close enough to make out exactly what he was saying.
Stupidity: The X-Men depart for space on a vehicle not designed for space, for an incredibly dangerous mission they know nothing about (and none of them can survive in space at that point), but don't suit up for it in the slightest - and with Nightcrawler and Quicksilver's powers as they are shown later, it'd be easy to do it without wasting time. Not only that, but Xavier communicates with NASA to get the briefing only after the X-Men have already departed.
Stupidity: Simon has told his wife Christine to never go into his shed/lab where he has dinosaurs chained. Christine is looking for her son Mark. Instead of searching the house (and finding Mark in his bedroom) or asking Simon to check the shed, Christine goes into the shed and is killed by a raptor. (00:02:30 - 00:04:58)
Stupidity: The whole movie necessarily has to be filled with stupidity (we're talking about a 9 months kid besting 3 adults), but there's one part perhaps not so obvious and that may be related to a mistake about the ransom note. When the bad guys watch the news, it's obvious that their original plan failed, since they cannot retrieve the money at the designed drop zone, the police have been called and they'd need to rethink the whole operation. Yet they make no comment about it and don't seem bothered by that at all.
Stupidity: Given Louise's character, it makes no sense at all for her to leave Thelma in charge of the money. She's known Thelma for years, and knows fully well how flaky Thelma is. And Louise is shown as a person who lives by "If you want something right, you've gotta do it yourself". She's responsible, perhaps even uptight, at that point in the movie. So it defies everything about her character that she would let Thelma guard the money - it smells like a device set up just to allow the money to be stolen.
Stupidity: The bullies run their car straight into someone they think is a total wimp (Goku) at full speed, crushing his bike. It's not a dystopian future, had Goku been a normal person they would have straight up murdered / crippled him for no reason at all. They are portrayed as a group of jocks, not homicidal maniacs committing roadkill on their way to school. It has also to be noted that Goku was parking his bike in a car parking spot, where nobody would just put a bicycle - but it is needed by the plot so that the bullies can casually crush his property. (00:06:35)
Stupidity: Why would Stanley say the shoes fell out of the sky? It happened under a bridge. Any normal person would instantly realise someone threw them off the bridge.
Suggested correction: It's an idiom/expression. When something turns up out of nowhere, we say "it came/fell from the sky." In fact, Mr. Sir says this to Stanley when he finds Stanley with his empty bag of sunflower seeds, "Where did this come from? Did it fall from the sky?" Obviously a sarcastic way of saying, "it didn't get there by itself, someone put it there." So the shoes obviously fell from the bridge and Stanley knows this because Zero refers to the bridge later in the movie.
Stupidity: The Foot Clan knows that April O'Neil is an ally of the Teenage Mutant Ninja Turtles. Since the Foot Clan hasn't been able to find the Teenage Mutant Ninja Turtles for where they live a easy solution would be for them to go to April and ask where are the Teenage Mutant Ninja Turtles. An explanation is never given in the movie for why the Foot Clan never use that easy solution.
Suggested correction: First of all, the Foot Clan at the beginning of the movie is disorganized. Secondly, upon Shredder's return, he plants a Foot soldier named Freddy into April's news crew in order to keep an eye on her and find out where the Turtles are. Then they change tactics when they discover there is still some of the mutagenic ooze around, which they then decide to use to create their own mutants to lure the Turtles out of hiding.