Well how exactly would they choose who would be suitable for the player and who not? Can we be sure that they would make every NPC player-sexual? I mean maybe they would decide to make Aymeric an female Elezen WoL interest only. Could you imagine the rage of a lot of people? Would they still make those romantic options killable? (Damn this would break ones heart even further...I mean the deaths are already quite painful if you like the NPC but if that one had a romantic story with the WoL..)