I don't think you can really analogize much about Twitter from the examples of OnlyFans and Tumblr... the porn/adult-content situation is a whole different can of worms than the stuff people get mad at Twitter about.
A more fair moderation system doesn't mean Twitter is going to turn into 4Chan. Everyone seems to hint that is going to happen, but have 0 evidence to support their claim. It just seems like some people are afraid some speech they disagree with might once again be allowed, like during early Twitter...it's almost like a power thing.
I think this is a sane and principled stand that is very different from: "I want to enable bigots."
rather, it sounds like a way to turn twitter into another in a long line of mostly-empty "freedom"-touting social networks that prioritized tolerance of abuse over user experience
as a Twitter shareholder, I'd prefer ElMu not ruin it, or my investment, like that