Not only does it have poor support for common hardware, it has artificially restricted support. What it does support, it supports reasonably well, but that hardly qualifies OSX as a system that supports mainstream hardware.
You get a terminal with bash or whatever shell you wish, which works great (none of the Cygwin crap). You can compile most non-GUI Linux apps for OS X (and many GUI ones). Etc.
I rarely run into things that I can do on Linux that I can't do on OS X.
Why has it been a dead-simple 5-minute thing to install those apps on Windows for years, but still tricky on MacOSX?
Why did it take, what 7 years, from the launch and immediate celebration of OSX, to get native GTK?
So, without knowing the answer to the above, I guess you could say I'd like it to be more like Windows (ducks).
The need for multiple binaries - (OS X 10.4/10.5) x (PowerPC/Intel) x (32/64 bit, maybe) - is also a pain. You can cross build, and you can munge multiple builds into a "universal binary", but it's not obvious enough to avoid the same discussions happening on every open source project's mailing list.