The problem with a "free speech" platform is that people value their anonymity, and that brings both good and bad with it. Unfortunately, making it pay-per-view would have to introduce doxxy payment methods.

Also, history shows that people are not willing to pay a small amount for such things, as sites for free e-mail/social media flourish, while paid ones remain tiny and obscure. Does anyone remember SomethingAwful?

I wonder if running a site with a crypto-currency protocol baked in would be possible. Basically pay the equivalent of a few pennies over a blockchain verification to make your post/comment go through. That could slow down bot-spam, and make it easier to regulate/block certain addresses if they even find it worthwhile to buy a chunk of crypto to do it. Even have those posts signed as a way to verify who someone is, as only they would hold the private key.