For the technically inclined, here’s why. First, it’s marginally less expensive. That’s not a super-important factor, but we want to be good stewards.
Second, it lets us run the CMS software we want, and that software integrates with my blogging toolchain. The current website is essentially a blog. I hope to begin podcasting again soon, and that will be another blog.
There are other minor technical considerations. The email is (IMHO) better, and I like the domain registrar. But the really big win is that the hosting company provides shell accounts, so whenever I need to, I can just scp over there get things sorted.