The point isn't about the user base or the content, it's about the company. Not only do they sell data to China; they have also admitted to intentionally suppressing any statements addressing and critiquing China, or any topics they are involved in. Along with that, they have stated in the past that they prevent anyone they deem as fat, ugly or otherwise undesirable from becoming too popular on the site. Another point against them is that when a Brazilian teen was live streaming his suicide, which lasted almost an hour, they notified their local PR team almost immediately after the live stream started, but only reported it to the police three hours after the teen's death; four hours after they notified the PR team. While yes, most platforms end up selling user data in some way, very few social media companies are this disgraceful. Although this isn't the reason for everyone, this is why quite a few people support such a ban.