https://marco.org/2009/02/26/the-main-reason-i-dont-allow-comments-is-that-i
The main reason I don’t allow comments is that I want to inspire debate. I think people do their best writing when they’re forced to defend their ideas on their own turf. It’s one thing to leave a comment on someone else’s blog, but quite another to put your argument in front of your own readers. It forces a level of consideration that, without fail, results in a higher quality exchange of ideas.
This is exactly the rationale behind using reblogs as a means of debate and discussion.