“Totally free” is not a benefit. I want a transactional relationship with a company that will compel them to help me when things go wrong.
But everyone that I know that uses it, hosts their own anyway (I don't agree with Moxie's thing of "people don't want to host their own servers and never will - clearly not true for some people). But that was beside the point anyway, open server design means you can choose who runs your server for you.