For the most part, a developer is allowed to put whatever they'd like in a video game. But, as with anything else, they are susceptible to the will of the market.
If a developer alienates a particular group, then they cannot rely on the support from that group.
The recent rise in outrage from these groups comes from them finally having a voice that they didn't before. It should be looked on as a triumph of our society, not a detriment.
Bet with Adamblaziken:
I bet that on launch the Nintendo Switch will have no built in in-game voice chat. He bets that it will. The winner gets six months of avatar control over the other user.