You do realize that you can fork the chain if you want, right? It isn't hard. You can also create an interface that shows only downvoted content or censors the people you don't want to have there. You can create your own second-layer token to incentivize usage of it for those you want there too. and control it centrally as you wish, like all the other tokens have. You can also go to other blockchains that are out there, like Blurt - sure, there might not be much activity there, but you can be the ones to make it active.
There are many more options too but,
What you are suggesting is ridiculous.
This is a social blockchain, there is a social dynamic to all operations.
I do not believe the double edge sword of exclusivity will do use any good here.
You can read my post about that;
https://peakd.com/hive-122315/@phusionphil/the-double-edge-sword-of-exclusivity