Choosing not to support a platform which may not be profitable is not "incredibly hostile." Don't forget when calculating profitability that you also have to a

Choosing not to support a platform which may not be profitable is not "incredibly hostile." Don't forget when calculating profitability that you also have to account for opportunity cost: the devs you hire to work on Linux could instead be working on improving your fledgling client for the much more profitable Windows platform. Valve is already over that hurdle with Steam, so their profitability calculations will be different. You can't draw a direct comparison. Like I said, I work on Linux. Trust me when I say there's a lot of very good reasons not to support it that have nothing to do with one's personal opinions of the platform, or whatever it is the OP meant by "incredibly hostile."