Its probably okay for some users, my point is, those "some users" is not a big enough number among computer users. I doubt it will be more than a million.
If you consider an OS for the desktop/laptop segment used by professionals, developers, power users, etc.-- you are probably correct.
But there are other OS environments:
-- enterprise users who only (ever) use a few apps on a LAN (analogous to dumb terminals of the past)
-- single-purpose appliance devices like TiVo, TimeCapsule, AppleTV, PSP, XBox, WII, Fedex hand-held Terminals, Portable POS terminals, etc.
-- multi-appliance devices such as smart phone, iPod Touch, PDA, Cameras, etc.
All the above are potential users of a new speciality [subset] OS.
This sector is growing much faster than the desktop/laptop sector.
One needs only look to Phil Shiller's preso on OSX at the WWDC.
John Gruber said:
Its simply a matter of users. During Phil Schillers keynote, he showed a graph of the OS X user base over time, with steady growth over the first part of this decade followed by a sharp jump from 25 to 75 million over the past two years. This figure was widely mis-cited, however, as showing growth in Mac OS X users. It did not. The graph said OS X, not Mac OS X, and what Apple meant to show were the combined number of users of Mac OS X and iPhone OS. It was a very misleading and poorly-designed chart.
http://daringfireball.net/2009/06/wwdc09_wrapup
The point is Apple's OSX (for all devices) tripled from 25 million users to 75 million users in the 2 years after the iPhone and iPod Touch became available.
It is not too unreasonable to predict that
mobile OS use will surpass
desktop/laptop OS use within the next few years.
Last count, there were more than 40 million mobile OSX users.
Dick