I've never once had an application in Linux crash the whole OS - or at least not so long as I've had physical access to the machine (I've had rouge database requests brick a server before because it took down sshd - but that's a different story)
In fact on the laptop I'm on now, the parent link crashed Firefox. But it OOM'ed and got killed before I even noticed there was a problem (and that's on a beefy desktop environment with compositing enabled too)
