The TVTropes page (which I am not linking to) notes Idiocracy as an example of a plot where everyone in the society is an idiot and the premise works. If that’s the actual point of the story, that’s different to doing it just to give yourself a plot at all.
This is essentially the premise of “Burn after Reading”.
Yes, but it has a clever subtext, which makes all the difference. Cf. Jack and Jill.
(I have often have a reaction similar to cloudlicker’s when confronted with bad storytelling in books/movies.)
The TVTropes page (which I am not linking to) notes Idiocracy as an example of a plot where everyone in the society is an idiot and the premise works. If that’s the actual point of the story, that’s different to doing it just to give yourself a plot at all.