Console users are happy to pay for the right to play online, via XBL though, while some PC gamers are happy to pay for a dedicated server.
(and many servers are free put up by GSPs such as Jolt, Wireplay etc).
Exactly, if they already pay for XBL they're not going to want to pay again are they? Microsoft sure as hell won't pay for them either.
As for the servers supplied by providers like that, they're loss leaders to advertise their own product, they couldn't support an entire game in the same manner without people buying the products.