And Blizzard have had a Linux client for WoW ever since alpha which testers were allowed to use up until the release of the game. But as we can see that client

And Blizzard have had a Linux client for WoW ever since alpha which testers were allowed to use up until the release of the game. But as we can see that client has yet to see the light again for the eight years that have passed after the games release. Big companies like Valve and Blizzard have a ton of different projects that never see the light of day. In the case of Linux clients it's most likely because the man hours needed even to support them doesn't pay back in new customers.