For me personally, one factor is that I have yet to be presented with romance options in game that have felt genuine. Some responses to the previous comic spoke of realism and consistency of characters, and if anyone's felt truly immersed in these video game romances, that's genuinely good for them.
To me, romance options being restricted by character gender just seem like content that's, well, being restricted by character gender. You are being prohibited from certain options and cut scenes unless you play as a gender you might well not want to play as, and this can be in very long games (or, in the case of Mass Effect, multiple games that remember what you did in previous ones).
I don't find that more immersive. I just find that limiting. Granted, there could be valid plot reasons for that, but I'm still not likely to respond with "I like the game more because of this."
Again, however, this is all general personal preferences. The more specific one gets, the more potential there is for exceptions.
Speaking of personal preferences, I would MUCH rather play matchmaker in a video game than try to get the protagonist to romance someone. Give me quests with the potential to make the ships I want to see happen set sail, and I'm there.