Plan 9 was not a product though. You seem to be arguing against the concept of research in the software world.
And it was only "research" because AT&T (or Lucent at the time?) couldn't sell it.
1995 was Lucent, and AT&T did enter the UNIX PC market in the 80's. I got to use a 3B2 in college in 91. Sadly, that was my first UNIX computer.