I think this argument is a classic example of a self-fulfilling prophecy. If you assume your audience's bigotry needs to be coddled and catered to, of course your audience is going to end up consisting of bigoted people, because everyone else is going to get fed up and leave.

Avatar: The Last Airbender had an all-Asian cast and no pre-existing audience from being a franchise, yet it trouched its contemporary The Batman in critical reception, awards, and fan dedication. I can't find Nielsen Ratings for The Batman, but ATLA was pretty much the top show of its targeted demographic whenever it aired, and given how many more fans it had among older viewers (i.e. those with their own discretionary funds), I'm betting its DVD sales were better, too. Next year we're getting The Last Airbender: Legend of Korra, a sequel starring a brown-skinned woman from a culture that's a fantasy version of Inuit cultures. The trailer aired at SDCC to explosive reception, and I would be very surprised if it didn't beat out Ultimate Spider-Man and whatever other Marvel/DC animated offerings come out next year.