While I do absolutely agree that single issue politics is a real thing like you showed, literally the only reply to your comment was "if you are a single issue voter, you're an idiot".
So I also think OP has a point here and we're talking more about the people who use the term as an ad hominem attack, which I certainly have seen plenty of. And now Lemmy has provided us with yet another example of people taking something legitimate and turning it into a weakness/attackable offence. Like some trolls and racist people on the right now talk about DEI in negative terms