Well lets say you want to talk about everyone who isn't straight basically, there's not really a good term to use. I prefer to use "everyone who isn't straight" I guess, which is why I used non het. (Non Het is a shortened way of me saying that but I can see how people can take offense) but there comes to times where sometimes you need to address this specific part of the community - how will you do it? You can't say the LGBT community in general if you didn't mean the trans people, the asexual people, the romantic minority people, etc. You really only mean the sexuality section tbh, so it comes to a point where sometimes we need to find a term that isnt offensive but can accurately get the message across.
Yeah, I see what you mean. As I said before I use queer as an umbrella term for basically people who just don't abide by societal expectations which is why I think non-het was a bit off putting, since queer could include heterosexual people who challenge societal norms of what a heterosexuality looks like.