Yes I know, your least-favorite idea goes here. But seriously, someone must have come up with the concept before. Like a bad get-rich-quick scheme could fall into this category, where joining the scheme makes people lose money and become more desperate, so they become more likely to do desperate things like invest more in the scheme. But it can apply to a number of other bad ideas.
Trickle-down is both the obvious example and a half-decent description. ‘It’ll go this way, for sure!’ Doesn’t.
But more generally it’s oppositional denialism. ‘Proving me wrong just makes me believe it harder!’
– Reddit user RanchMeBroTendo, a depressing number of years ago.