I totally agree, Paul.
It's the social media aspect that keeps me on Flickr - I have loads of views and comments on my pics, and that kind of stuff is hard to capture on a self-hosted solution as you don't get the same kind of traction. Obviously I have all my photos backed up, but you can't backup views, comments and social engagement.
We had this debate when The Reg reported that Flickr deleted some chap's account and people were quck to ask why he didn't have backups. He did have backups, of his photos. But that was not what he had lost. It would be like eBay deleting your account and you losing all your seller history and feedback rating - it's not something you can back up, nor something you can self-host necessarily.
As you say, though, you are at the mercy of the provider for stuff like this sadly.