Well, at least for several threat models, "your site to CF" is at least slightly better than "CF to clients". It's not vulnerable to things like unsecured wi-fi sniffing. Then again, neither are self-signed certs and for some reason all browsers consider them even worse than no cert.

On the other hand, it doesn't protect against government spying, but then again, I think some governments straight-up MitM HTTPS traffic anyway. For instance:

https://news.ycombinator.com/item?id=10663843