I know this may come as a shock, but the majority of the desktop market is not developers (though no doubt an appreciable percentage of Linux desktop users is, which is why his view is so skewed). What killed Linux as a desktop OS is probably a very complicated and nuanced confluence of factors, but I think Microsoft's embedded position and anticompetitive tactics have more to do with it than the preferences of server developers, as does the lack of grandma-compliant plug and play and usability.
That said, looking at things another way, as we move into device-based computing, GNU/Linux by way of Android is very competitive on the palmtop, if not the desktop, in the same way that Mach/BSD is by way of Darwin/iOS.
UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things. -- Doug Gwyn