Maybe Microsoft's code doesn't cause crashes any more, but 3rd party drivers and shoddy OEM hardware are definitely still to blame. Users don't care why their stuff crashes, only that it does. And first hand, I see XP-era machines crash less after converting them to Ubuntu. I haven't tested a Vista machine, I've never seen anyone run one.

Re: ECC ram, my non-server, "consumer" linux boxes typically have uptimes of 100,200,300 days. They only go down for hard drive failures and OS upgrades.