[ubuntu-x] X.org stability goals? i.e. should X server ever crash?

[Dan Kegel]

Sorry if this is the wrong forum, but: the bug
https://bugs.launchpad.net/ubuntu/+source/wine/+bug/183922
is an x.org crash that seems to be misfiled; it ought to
be under xorg, but various people keep saying
"X can crash, that's ok, so this is Wine's fault".

Can I get a clarification on X's stability requirements?
IMHO it's something like
"The X server must never ever crash as a result of
running a non-root app, even a badly written one.
Any such crash is a bug either in X or in the
currently loaded graphics drivers."

Thanks,
Dan