Over the years I've read a fair number of blogs some of which suddenly disappeared which saddens me because those were valuable resources. I think many geeks swear on self-hosting their blog because of the advanced customizability and control over every single aspect of their blog. I cannot blame them because I'm one of them.
The problem is that this way your blog isn't very resilient. What happens if you get hit by a train? That's right, your bank account will eventually get depleted and your hosting provider will shut down your server, making your blog vanish. You may say that I'm being absurd talking about death but if you consider your blog your legacy just as I do then you should also be concerned.
After all this mumbo-jumbo let me introduce you WordPress static blog generator. According to my knowledge this is pretty much the most convenient way to back up your WordPress posts, pages and comments as static HTML pages which you can easily browse and push to GitHub Pages, preserving your blog for eternity.