[jrochkind1]

Yes, exactly!

If they hadn't had on-the-ground experience of the plan-9 version, and been able to see what parts of it they wanted to keep and what parts needed to be done different from that actual experience...

Often you can't build the polished thing until you have experienced the thing before.

Lately I get discouraged that there seems to be not so much attention to "prior art" in software development, that's the only way to make progress!