And yeah, the !important should be working. I've never used Stylish, but something's clearly broken -- in any case, your beef should be with Stylish or your browser, not with the author/developer of the blog. If you stick to a user stylesheet in your browser it should be guaranteed to work -- after all, that's the whole point of them, so that people with visual disabilities can override default styling.
So, I don't really get what the problem is. Inline styles are an integral part of the web (and are particularly, and correctly, suited to blog posts), and user stylesheets generally allow you to override them, so you can use dyslexic fonts if you choose.
You haven't even tested it, nor do you even really know what Stylish is, it seems, and you're arguing with conviction.
What am I doing here?
Thanks for the advice. I'll keep my distance then.