It's not surprising considering how bad Tether was in terms of transparency, etc...
i don't think it has anything to do with that.
when you think about it "stable coin" is another subcategory of altcoins so it also inherits all the issues that the altcoins have. in short everything is open source and easy to fork and for years people have been creating their own altcoins by copying work of others and 99% of them have been doing it to make money. this subcategory is not any different either, they are still doing it to make money and gain some power in this market.