Re: So, not great, not terrible
The linux boxes you mentioned probably run 10% of the games the Windows ones do, support fewer hardware configurations and are less of a target than Windows PCs purely due to market share.
I'm all for Linux but being a blind fan boy of any product isn't a great idea, if/when (very much if) Linux really hits mainstream use it'll be the top target, we've all seen how Mac OS has gradually been more of a target even after making the big switch to BDS code base years ago, as Linux becomes more popular it'll just be more of a target and Torvalds will have more epic screaming sessions.