[vetinari]

Mac OS breaks compatibility too, so there is nothing that could be better than on Linux side.

Actually, if you really care, you can still run a.out and glibc5 ELF userland binaries on Linux. On the other side, any m68k or ppc for classic apps are no-go on OSX, as well as some ppc-for-osx. Also for third party drivers, you need version for specific OSX point release, they are not generally very compatible.

There are also entire classes of hardware that are unusable on OSX, period. (I remember wasting particularly lot of time on trying to get IrDA run on OSX with a little bit more than just IRCOMM. On Linux, it worked out of the box.)