To those of us who are, it sounds excessively clinical, most of us dont like thinking of our sexuality in a clinical way. Also the poster is not wrong, talking about homosexuality, is cool and okay, calling someone a homosexual is often a language flag that they may be less than open minded.
This might all be true, but is there ever going to be a point where we assume positive intent? We shouldn’t be inferring deep-seeded psychological attributes in every day communication. It’s super likely that nothing at all was meant by using the clinical term.
I didnt see a lack of good faith in the discussion, it was more of a "hey, you might wanna know, that using that particular word associates you with this group you might not want association with" - which if anything is an assertion that requires good faith to make.
