In fact, one of the main problems is that there's not an "official"
bug reporting tool beyond email. Many kernel developers didn't
like bugzilla when it was started, and as for today, many core
kernel developers still do not even _look_ at bugzilla.kernel.org.
The hard work of akpm and some cool people like the acpi guys has
made possible lately to start using bugzilla as a sort of
"official" bugzilla, but there're still many kernel developers
that need to be convinced (and many bugzilla features that need
to be polished). AFAIK, people is going to talk seriusly about
this in OLS.