Huh? Steam is a platform for Windows games and was built because MS didn't offer such a thing. Their handheld devices run Linux and a Windows emulator.
I don't think they ever cared about Macs. The Mac gaming market is vanishingly small. Windows gaming is bigger than all other platforms (including consoles) put together.
I don't think they ever cared about Macs. The Mac gaming market is vanishingly small. Windows gaming is bigger than all other platforms (including consoles) put together.