I didn't let that broad-brushing stand unanswered, especially because the most common implication of that is "(specific trendy drug) will solve your problems because it solved mine"

Based on what I've seen irl and online, I'd say that such sentiments in this case moreso may come from a place of despair and suffering, not so much arrogance nor shilling of snake oil, especially if the person has tried therapy before in good faith. Not saying that shitheads and "Just X bro"-scientist roganites don't exist though, because you absolutely do describe a widespread and life-threatening tendency especially among men, but it may not apply to this specific case that OP mentioned earlier.

I was speaking from the perspective of someone that had to live with (for a time) someone who didn't even start therapy at all (except bragging about lying during initial counseling before dropping out of college), going the all-American route of "nothing is wrong if no diagnosis is made," and instead self-medicated while gradually wasting away, starting to steal from me to keep the self-medication going to the point of me having to move out for my own sake.

That is beyond horrifying. My condolences.