OSX accounts for just 2.93% of steam users - and at most, assuming they have the most recent/powerful hardware - which they don't - 50% of that value would be able to run the game. That sure doesn't seem worth it to me.
Check the official FAQ please: https://wiki.beamng.com/BeamNG_FAQ#...e_Mac.2FLinux.2FXbox.2FPlayStation_support.3F