You've come very close -- without *quite* saying it -- to saying that
`core' is simply not allowed to ever reject code from someone.  That's
just over the top -- and I sincerely doubt that the NetBSD project
will *never* work that way.  It is precisely `core's job as technical
arbiter to decide what goes in and what doesn't.  If the contributor
decides to be overly upset about this, well... `send something useful
next time'.

As for the particular case you alluded to: you're seriously
misrepresenting the facts.  There was, in fact, an explanation on one
of the mailing lists at the time.  (And no, I don't intend to dig it
up.)