
I’ve never heard this and I’m genuinely interested. I do use monosexual to refer to people that aren’t bi sometimes (in the same way that allosexual is used by asexual people to refer to people that aren’t asexual) because I think it can be a useful term. Why do you feel it’s inaccurate?
I have primarily heard it online when people are talking about lesbians. Like I have primarily seen it when ppl are complaining about les4les, for example, “the monosexual lesbians oppressed bisexuals by being les4les. They treat just like the straight monosexuals.” I am sure it is also used in other context but when I have seen it used it is to claim that lesbians, gay men, and straight ppl are oppressing bisexuals and ppl who fall under the bi umbrella