[skwiddor]

It gets plenty of attention. IBM runs it on Blue Gene. LANL run it on their cluster. There's about 50 active posters to the 9fans mailing list. Features are regularly poorly copied to Linux (rabbit shaped peg, penguin shaped hole). Plenty of people say "how can usermode be fast" and yet Coriad use it in their AoE enterprise disk products, of which there are over 1000 installations afaik (I'm not a Coriad rep).

I also earn my living plan9 & inferno programming and I know at least 10 other people who are equally blessed (not all at the same place as I).