Don't forget, Pyro and HT did Warbirds when it supported Mac, so they know very well what the additional costs and benefits are. We can speculate all we like, but they've got experience to help them decide. Obviously, it isn't worth doing.
Now as for Linux... not a chance. What a complete waste of time that would be. Linux is not even close to being a decent desktop OS. It makes a fine server OS, but the lack of any standardization kills it as a desktop gaming platform. You don't even have to get into it's tiny installed base.
Oh and btw, it's easy to grow your market share by huge % numbers when it's tiny to begin with.
Until Linux doubles Mac's market share as a desktop OS I don't know why anybody would consider it. Nevermind the obvious problems with standardization that the Linux inherited from it's Unix roots. IMHO doing anything other than pure Windows would be a complete waste of resources. There isn't nearly enough folks out there running anything else to make it worthwhile.
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Lephturn - Chief Trainer
A member of The Flying Pigs
http://www.flyingpigs.com "A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"