Yes…we know and its not actually Steinberg or Cubase that is so buggy. 
Please don’t kill the messenger…
As you perhaps already know people on PC doesn’t suffer on many of these bugs as users on MAC OSX do and I can explain why.
Its Mac and Apple that can’t keep up with rest of the world and “modern code” and technology especially new graphic codes that works perfectly well on Windows platforms.
Is it fair that Steinberg’s products stop evolve because of the lack of progress on apple behalf? 
OSX has always been behind in graphic and use of second rate graphic cards even though its gone better lately.
As far as I understand majority programmers that work on Steinberg, base the program on C++ code.
So do NI, Waves, Softtube, UAD etc…
I would guess Steinberg use some of the C++ code and try to ported them to Unix code instead in a later stage.
There are many other companies that don’t even bother with APPLE or MAC support or even use them. Products like computer games, Xbox-game (program exclusive on windows with help of C++ and other programs), Playstation-game (program exclusive on windows with help of C++ and other programs),… other programs, advance animation programs. CAD,… etc… All on WINDOWS exclusive.
You don’t find so many games or animation and special film effects program on OSX do you?
No, all are on PC Windows, and they have been all along.
I’m not saying that windows cubase users are all free from bugs. No, sure we all has some bugs too, but not as many as you users on MAC.
Perhaps that is why it might be wise to end mac support for good and keep the focus on develop Cubase on windows instead. All the programmers can focus on make a greater Cubase Nuendo instead of trying to make it work on OSX all day long. Windows 7 and 8 is a open system that you can build and specify with individual components specific for your own needs. It also the performance platform working with Audio, film, game, animations or whatever.
That is the truth, even if it hurts. 
Best Regards
Freddie 