That's a little simplistic.  The x86 is a lousy architecture,
and you're right about the compilers etc.  But all those
lousy drivers, VGAs, USB floppies, it goes on and on.
Are any two the same?  I doubt it.  That's the horror of
PCs, yet is a perhaps unavoidable consequence of the
history that made the PC dominant (c.f. the Mac).

The PC kernel for Plan 9 is huge because of all the drivers
it must have to run on all devices.  Sure we could have
(and perhaps should have) loadable device drivers,
but that is a solution to a problem that shouldn't exist.

-rob