I dunno, man... Between
A) some guy who does some dumb thing on impulse, before their brain has time to kick into gear (e.g., ****, I dropped my phone, need to get it back)
and
B) a guy who spends several months working on something extremely stupid, ignoring all the comments he must have gotten in the meantime about why it's stupid, and even disregards his own first hand evidence that the first time around their home made parachute got shredded...
Pretty sure I'd vote for B as having done the gene pool the biggest service by removing himself from it.
I mean, even smart people occasionally do something dumb on impulse, by not taking a few seconds to think it through. But someone who did put a lot of effort over a long time span into thinking it through, and still came up and went through with something extremely stupid, well, I think that they pretty much proved beyond any reasonable doubt that that IS their intellectual level. If the charge was having a working brain, no jury would find them guilty