Actually I'm quite happy that I've started to use them a few months ago, they actually just "take" ~25% from each sale to cover their bandwidth/server costs, and I've honestly spent more than those 25% for my Movie gallery servers. And I'm also pretty sure that many Thumb MGP/TGP owners spend more than 25% of their income for hosting.
Additionally you'd have to count in the time you spend with maintaining your own servers, doing updates, fixing this and that, etc. And the money you're spending for "oversized" webservers, i.e. you buy 100 mbps, but only use ~60 mbps for the first few months, etc.
All those things cost time and money
