I prefer this. Like Silk Fox in JE said, "I've never felt this way about any man or woman". Choosing instead to make a distinction only makes it seem like there is something wrong or abnormal with those feelings.
To an extent I disagree.
Saying "I've never felt this way about a woman." since quite possibly Vette(or another female in question) may have felt that way about a man is entirely reasonable. But as it's been pointed out, I'd like to see some variety, I think it's pretty obvious that DS Jaesa really doesn't care to much who or what she gets nookie from, and the same is probably true for other characters as well.
Just as Theran flirts with fem-consular in your first conversation with him, some people see it and know they want it. Some folks may need to warm up to the idea, even Malavi needs to be slow-cooked to even show some feelings for the fem-warrior. He's quite possibly a character who's never thought about his sexuality, or sexuality of any sort at all!
But, again, it is that diversity among how companions approach the player about romance that makes it fun to play through all the different stories. I still feel that the simplest and most player-empowering option would be to select an orientation at character creation. "heterosexual", "homosexual", "neutral/bisexual" "none", which would effectively toggle which romances are active for you in the game.