Also Bill was gay in the first game
Bill is a good example of how you can do inclusion without hammering it in. IMO sexuality of a character really only matters if the story involves romantic arcs. Otherwise the sexuality can be used kind as a passive "oh hey this character is gay btw." But it's meaningless if they have no relationships in the story.
Bill is kind of revealed to be gay almost passively, it adds a bit to his backstory but otherwise doesn't define him as a character.
To me a badly written character is when their only defining charactization is superficial. When being LBGT is the only thing that defines them, as opposed to their motivations, conflicts, and overall arch (if it exists).
There are a few other characters that are done in a similar fashion to BIll that i can't 100% recall right now. But Tanis from Boarderlands is one. During conversations or audio logs she reveals that her lover is killed during one of her scientific outings, but it isn't a relationship that the character solely relies on. Tanis is a talented, crazy but brilliant science lady in the series and her lesbianism is just flavor on top of a funny and well done character.