Commenting is a privilege, not a right. You have to earn it.
While early bloggers were generous, giving their rare online spaces up to public discussion, there is no need to feel so generous any more. Starting one’s own blog is easy these days, and ranting on social media is even easier. There is plenty of space for people to discuss stuff, and that does not have to happen on your site – the era of such generosity is mostly over, and most veteran bloggers have severely tightened their commenting rules over the years.
And yes, some blogs are still rich with vibrant commenting communities – e.g., Atrios, Pharyngula, etc. They have people there who talk to each other every day, often ignoring the topic of the actual post.
I just thought those last two lines were extra-amusing. Yeah, uh, the lush, green grass above my septic field is due to similarly "rich" and "vibrant" soil, if you know what I mean. Nothing more needs to be said about the Jonestown that Peezus's comments have turned into, beyond what he's said himself, but honestly, Eschaton? If there exists a more content-free blog with an even larger group of babbling dimwits in the comments, I seriously don't want to know about it.
Heywood said the other day that he'd like to have a more active comment section; I told him he should be careful what he wishes for. You can argue with me all you want, but lemme just warn you, the day you bastards show up here just to gab to each other about your personal lives is the day I release the hounds.