Except it doesn't drive away gamers who want to preview or discuss games. It's like the people who make a false equivalence that by spending 2 billion on the Mars rover mission, we have somehow taken away from funding (insert social justice issue on Earth). The audience for the "thot streams" isn't the same audience and I doubt audience is being "stolen" from other "regular" streamers.
The only semi-plausible argument one could make to "stolen audience" is regarding female gamers who make themselves more prominent on webcam and they are attractive, basically using their looks as a means to boost viewership. But again, what are your viewers there for? If it is really a true stolen audience situation and they are only there because "pretty lady", then in theory you're just stealing audience from someone who is capitalizing on the "pretty lady" category.
But again, if you are truthful about it, that is nothing new. This is no downfall of society. This is literally marketing 101. Using an attractive model (male or female) to sell a product is one of the oldest capitalistic tricks in the book, because it works. Except on a stream, the product you are selling is your brand (aka you).
If you look at successful people on Twitch, they have 1 or more of the following. If you can hit on 2 or more, all the better:
1) They have skill
2) They have looks
3) They have personality/are funny
4) They have a gimmick
Same formula exists for all sorts of things outside of streaming, be it pro-sports or even politics