While the underlying OS might be more robust (and I don't seriously think there's much in it between Windows, Linux, the *BSDs and OS X these days), if your display driver crashes, the operating system might as well have crashed. Xorg is teething at the moment.
A shit ATI driver (supplied by ATI) was the cause of some serious instability in my Vista installation. The kernel never blinked, but as far as I was concerned, it was titsup.com.
Of course, none of the aforementioned "operating systems" hold a candle to Proper Software like OS/400 and OpenVMS when it comes to "not falling apart at critical moments".