Thats something I don't understand. Blizzard games are always Mac and win at launch. Why can't do that other Devs? I mean in the last few years Apple users were more than win users. Sure win is currently at the top. But actual MacBooks pros and iMacs are fumast enough to run these kind of games.
Btw I playing on a well fast pc. I just want to support Apple users here!
The two biggest differences between OSX and Windows are the underlying operating system architecture, and the graphics APIs (OpenGL vs DirectX). Frontier have already ported the Cobra engine to OSX for Elite: Dangerous (so the OS architecture has presumably been dealt with already), but there's still work to do on a per-game basis, such as shader conversion. There may be other reasons why porting to OSX may be non-trivial (for example, if Frontier are using compute shaders for crowd simulation, which aren't supported in the version of OpenGL that's on Mac; this is a current issue with the 'Horizons' season of Elite).
Assuming the port is viable given graphics API support, it wouldn't surprise me if Frontier do get around to a Mac port at some point. It will depend on resource availability I guess, and this is somewhere that Blizzard is at an advantage: they can afford to employ platform teams full-time, whereas Frontier probably cannot.
Whether they port to Linux is anyone's guess. I suspect the reluctance to do so might be down to lack of good driver support. Frontier like to push GPU hardware, so poorly supported OEM drivers would completely block progress. If the Steam Machine architecture takes off, maybe AMD and Nvidia will start to improve their Linux driver support.