Users generally don't know or care if the issue is a bug in Chrome or not. To them the problem is just that Chrome is not working. So, we try to fix it where we can. We have code in Chrome to block third-party hook DLLs that we've identified as making the the browser unstable. We have watchdog code to prevent excessive resource consumption and hangs caused by misbehaving web content or plugins. And while we can't fix bad hardware, we do have signals that attempt to narrow it down as a cause.

That's not to say that some portion of crashes in Chrome are not caused by our own bugs that slipped through our various QA and testing processes. Certainly, those do exist, but in terms of crash rates they are dwarfed by the causes I listed previously.