Being bland has nothing to do with sexual orientation. Being straight doesn't make you interesting.
As for the NPCs, they aren't real people. They should be convincing, but its the player that matters. Just because an experience is uncommon doesn't make it invalid. Live how you wish, and grant others the same freedom.
What makes you interesting is having a defined character with likes and dislikes instead of jumping into the bed with everyone and everything as long as it is controlled by the player. For example a companion who has a dwarf fetish and would only romance them (and male gnomes if they have a beard) is much more memorable and interesting than the current sex robots.