While "single source" is a major MS selling point it's not really true. The people responsible for Windows drivers often point fingers at each other. Manufacturers state that it's something else you installed that broke the operating system. Microsoft might help you.. for $129USD or so an hour. Or they might just point out that the driver you're using isn't "certified" by them to work so you'll need to beg the vendor. Drivers in the Linux kernel have a clear cut maintainer. If the driver is currently available then the maintainer's name is generally stamped right in the source directory along with how to get ahold of someone if you're having trouble. False comparison.
On Windows, the vendor of the H/W is responsible for the drivers. On Linux, it's the maintainer.
Both the Windows vendor and the Linux maintainer can say that something else that you installed broke the OS.
Yes but his point was that windows folks we will call them OM$ers will crow that there is a single source for development of the software controlling your hardware, that is no more true for Windows than it is for Linux..