Most others, including its central premise about everything actually being a file, were not (adopted or successful), and turned out they weren't a big deal.
If from one product with 1 central premise and 10 new features the world only adopts 2 of those features, I'd still call it a "total failure" market-and-adoption wise, and a waste of time for those building it.
They could have built those 2 features independently anyway.
Except they are, because Linux reinvented them decades later with lots of hype, but worse, in the form of user-level file systems and containers like Docker.
> They could have built those 2 features independently anyway.
Except you can't know which features will be a hit in advance, so your research prototype is only a failure if it never gets any adoption, and never inspires something better. Otherwise it was successful in exploring a design space, even if the result is negative.
Your argument is the same fallacy as the belief that publishing negative scientific results isn't important. Documenting failed experiments is just as important to growing our understanding as documenting successes.
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.