Mac was actually doing pretty decently for game a few years back. A pretty big chunk of the games on Steam, including many of the high profile games, were available on OSX. Dropping 32-bit support set things back immensely, however. With that one decision, Apple made the number of games available to OSX users a small fraction of the amount that was available before.
PowerPC binaries are no longer usable, x86 binaries are no longer usable, I don't see why they wouldn't do it again in the name of streamlining the platform.
And Apple is working as hard as possible to remove it as soon as possible.