That's not to say someone couldn't come along and do with Linux what Apple did with Mach/BSD/NeXT. A focused Linux-based OS with a seamless new UI and app suite (and good APIs) could be great. In fact, that's one of the things that I like about the Chrome OS idea, no matter how silly it might seem to just throw Chrome on a "bag of drivers."
The problem, of course, is the effort. Software is hard.
Apple basically started from scratch in 2002. A big company with a strong consumer brand, proven track record and lots of cash could do it. Google is such a company. Especially coupled with a paradine shift to web apps and a clear revenue model as a result. I wrote about this here: http://blog.richardcunningham.co.uk/2009/07/what-googles-chr...
Mac OS X got it's first (server) release in 1999. And even that was a reboot of Nextstep which was originally released in 1989.
Of course, the whole point of Chrome OS is (apparently) to not have a traditional GUI and apps, just a browser, which is most of the stuff Apple had to add onto BSD.
I meant my comment in the context of the message I replied to. In that in 2002 they first tried to push a new OS to the desktop market as it was then. From what I heard about it, nextstep was not anymore advanced compared to the rest of the market than Linux/Ubuntu/Gnome is now to it's market.
I don't believe any company could afford to start back right down to the kernel and low level libraries for a new desktop OS, even it was just going to run a web browser. I would say that any competitor to Apple and Microsoft would have to use a Linux kernel, CUPS etc. as a base - just as OS X used NextStep/BSD as base.
The problem, of course, is the effort. Software is hard.