As my mail quoted in
https://www.cl.cam.ac.uk/~mgk25/ucs/utf-8-history.txt says,
Ken worked out a new packing that avoided all the problems with the
existing ones. He didn't alter Prosser's encoding. UTF-8, as it was later
called, was not based on anything but it was deeply informed by a couple of
years of work coming to grips with the problem of programming with
multibyte characters. What Prosser did do, and what we - all of us - are
very grateful for, is start the conversation about replacing UTF with
something practical.
(Speaking of design by committee, the multibyte stuff in C89 was atrocious,
and I heard was done in committee to get someone, perhaps the Japanese, to
sign off.)
Regarding windows, Nathan Myrhvold visited Bell Labs around this time, and
we tried to talk to him about this, but he wasn't interested, claiming they
had it all worked out. We later learned what he meant, and lamented. Not
the only time someone wasn't open to hear an idea that might be worth
hearing, but an educational one.
It's important historically to understand how all the forces came together
that day. The world was ready for a solution to international text, the
proposed character set was acceptable to most but the ASCII compatibility
issues were unbearable, the proposed solution to that was noxious, various
committees were starting to solve the problem in committee, leading to
technical briefs of varying quality, none right, and somehow a phone call
was made one afternoon to a couple of people who had been thinking and
working these issues for ages, one of whom was a genius. And it all worked
out, which is truly unusual.
-rob