As someone who is personally a bad idea machine, I feel qualifies to respond here. There's a lot to unpack here, but I think it boils down to being good at winnowing down a solution space - which is pretty squarely a Systems Engineering skill - specifically at the concept design phase.
The truth is, when a problem is very open, there are generally far - far... far more bad candidate solutions than "good" ones. So, being able to articulately explain why an idea is bad or perhaps more likely has some mix of "good" and "bad" elements, in a manner that is irrefutable and does not diminish the courage of engineers proposing the concept in the first place, is a critical skill.
I think the key to highlighting this skill on your resume isn't stating that you know how to simply identify 'bad' solutions and say no to them, but rather that you were able to identify where solutions fell short and then led the individual or team to a solution that worked and was far superior to alternatives. After all, that's what matters. Anyone can say "no" and because of the large disparity between good and bad ideas (as described above), you'll have plenty of opportunity to do so - so, that's not very impressive. Finding the good solution [needle in the hay stack] is the skill you want to highlight... with substantive examples.
If your interested in this topic of winnowing a design space down, you may be interested in a method called Set Based Design - which is a winnowing method for mutli-objective problem sets developed by Toyota and can accelerare/automate the winnowing process.