I am disappoint wrote...
It doesn't matter what happens ingame, if that character is open to both sexes then that character is bi.
It doesn't matter if they don't show/tell the player they're bi, they're still bi.
So I'm a homophobic just because I don't believe every male in the world should be labeled as bi and free for the taking.
This isn't even about gay characters, you don't think their should not be any gay or straight characters, in fact you're homophobic one.
You are mistaken. My way of doing things would allow the player to decide the sexual orientation of each member of the pool of romanceable characters.
There is no 'canon romance' for Shepard, so there need not be any 'canon sexuality' for any of the LIs, unless a past relationship is a part of their backstory as it was for Thane. In thich case he would appear bisexual in the playthrough of a male Shepard that wished to romance him.
The same for Garrus, considering his conversation with Shepard about QCC in ME2. However, if you don't pursue a romance with him, you are free to see him as strictly straight. Remember: no canon romances.
Now, say you're playing a female and romance Tali. We don't know of any past relationships, so you would be justified in viewing her as a lesbian.
Saying that Garrus would need to be seen as bisexual if someone romanced him is like saying the Rachni queen is killed in ME1, regardless of player choice.