Maybe this doesn't make any sense, but when I write a blog post, I don't necessarily want lots of people to read it. My blog is primarily for me, the public nature of it just forces me to think about what I'm writing a bit more, and try to articulate my thoughts better.

It seems that the main reason you'd post to a "blog platform" rather than just your own website or some GitHub pages thing is to get more people to read it, so I've never really been attracted to any of these things.