Earlier quoted context omitted.
Well, if you're going to trot out quotes from the 80s (more precisely, 1987, Henry Spencer), you should be aware that Microsoft made and sold one of the first commercial Unixes: Xenix. And they made it in 1980, long before your quote. https://en.wikipedia.org/wiki/Xenix -> "In the mid-to-late 1980s, Xenix was the most common Unix variant, measured according to the number of machines on which it was installed.[1][2] M…
Apple successfully leveraged UNIX to develop macOS (officially UNIX) from which they developed iOS. Google successfully managed to leverage the Linux kernel (Unix-like) and Java to develop Android. Windows Phone, on the other hand, flopped.
1. 1980 to 1998 for Google, 18 years -> that's awfully close to 2 decades.
2.1980 to 2001 for Apple, 21 years -> that's more than 2 decades.
So your counter examples confirm what I said.
3. Windows Phone and family failed because of marketing blunders, not because of tech. MS-DOS and Windows succeeded because of marketing prowess, not because of tech.
4. The mainstream market just wasn't ready for Unix for a long time. The biggest Unix success was Sun, for a long time, and Microsoft absolutely dwarfed Sun for most of their existence. Further proof that my statement was right.