That our companions sexuality is retroactively created during our playthrough is not necessarily true Niara, it's a way of rationalizing the design choice.

That said, people have been conditioned by games not to expect NPCs to behave realistically with regards romance.

Also Konmehn, I don't think people look to video games to learn social skills, in fact related to the above, they're interested in less complicated exchanges. The problem to me of herosexual characters is that it's lazy, when it happens I see the game falling short of a character. Actually putting it in D&D, herosexual characters are a railroad. "You enter a chamber with two doors...but don't worry whichever you choose, it won't matter."