Idiot Plots and 28 Weeks Later

Spoilers for a ten year old movie or whatever.

Thought I'd talk about Idiot Plots, these are stories that require the characters to be complete morons to drive the events of the story, you see it a lot, whenever characters decide to split up to explore the abandoned asylum, or when someone goes into the basement by himself, or any number of other options that we have all seen a bunch of times and shouted at the screen in exasperation.
Possibly the best example of this would be 28 Weeks Later.

28 Weeks Later is a horrible movie.

So you probably know the movie 28 Days Later, when foolish animal rights activists decide to hug diseased monkeys for some reason and then turn into fast zombies, it was a pretty solid creepy zombie flick. It's sequel totally isn't though.

Taking place some months after the infection wiped out most in Britain, a coalition of other governments and natives who were out of the country are attempting to take the island back, this should be pretty easy as the infected still require food, but due to their disease don't actually eat, and thus have all starved or dehydrated. Still, they are proceeding pretty cautiously, sort of.

Despite the incredible caution and restrictions on movement, two children manage to escape the clean zone and go looking for their mom, who had been left behind for some reason, a pair of preteens evade military guards and get past locked gates and fences, they do find their mother, who has not done well during the occupation, but is still alive despite her wounds.

She is placed in quarantine, which is wise, but then her husband, just sort of walks in and kisses her, by this point we know the infection is spread by bodily fluids, so the husband is an incredible idiot and the results are pretty predictable, as the infection spreads, the emergency plan is apparently to lock everybody in a dark basement of a parking garage, presumably to make it easier to get everyone killed, which happens.

And so on and so forth, if at any point any of a number of characters acted like the smart, competent people they are supposed to be, this movie doesn't happen, but literally every moment of tension and plot twist requires the characters to be more brainless than the zombies, who at least acted exactly as they were supposed to.

It is a sign of incompetent writers, they want to get to the carnage or just to the next scene, and they just pull whatever out of their ass so they can move on. I dunno, it just bugs me.