The sign up process is kind of user hostile (or at least was a couple of months ago, they improved it a lot). People don’t really want to have to figure out which server to sign up to if they barely know what a server is.
They’re probably not talking about the actual conversations on Mastodon (although there’s definitely some condescension there, like if you dare to post an image without alt text they’ll come out).
They were only for the free market if they could force it on others.