You know what I really wonder, though? Not even the NPCs can be gay. Nowhere in all the galaxy have I ever seen an indication from background NPCs that they might prefer a lap dance from someone who isn't a woman - or that they be wanting to be chatted up by the lady in the Mandalorian armour, rather than the sleazy wanna-be smuggler who just dragged himself out of the latrine. That takes an outstanding amount of effort and forethought, I say.
To be entirely honest, that takes no effort or forethought at all. If you don't identify with homosexuality, it is easy to not include it when crafting a story -- just as if you are homosexual, the lack of it in story seems glaring.