This approach is incredibly open to abuse. Reddit implemented this to a lesser degree and abuse already started happening. By blocking everybody who disagrees with you, you can start threads that are only visible to lurkers and your supporters, creating a warped perception of public opinion and false consensus.
Porn Historically Decides Tech Adoption... Fediverse? ( kbin.social )
Historically, porn has organically decided which platform or formats become dominant. It's incredibly anti-censorship, but walks many fine lines....