Even though gay or straight people are not literally assembled in one big group, I don't see the problem in referring to them as a "group" of people who share a certain characteristic, especially if the point is that they are being discriminated exactly on base of that characteristic. And a socialist struggle can still directly pay attention to social issues without getting caught up in idpol or losing the primary focus on class conflict - this is not a black/white distinction. What I said was about ensuring equal rights, not dividing people based on some identity bullcrap.