A game can stillbe fun and engaging while having LGBT characters (look at NV), the problem is that way too many people believe that everything, from the food we eat to the movies we watch, must be a political statement. They forget about fun, depth and what makes thing memorable and good for the sake of parroting their political points and making everything into a mouthpiece. And even if they don't buy the game, they are terribly annoying and loud, usually pushing people less rabid than them into following their bullying campaigns. And it's not that companies yield because they believe it will get them more sales, it's because they want to appease to the peasants so they don't get shit flinged at them. That, or a pass to push any sort of crap on their consumerbase and shield themselves on "what is good and great". We have seen it time and time again in the last years, and unless there is some pushback, all big game companies will be rife with NPCs.
Also, those kind of characters still exist, but not in mainstream games because of the obvious bad press that will come from having that character. The conservatives will get pissy as well as the SJWs for having someone that is sex-happy, who is horny and happy and has no qualms about it. You can still find these kind of characters, but only in porn games where people know what they are getting into.