Comment by BadBadJellyBean

The thing is not just about distros and big developers it is about every developer out there who wants to write system software. Instead of doing the work to support multiple different APIs they can concentrate on the software. Its just easier. You don't have to track the compatability of different tools.

For many people Linux is not an academic exercise. It is a tool they want to use. The don't care to use a different network manager or resolver.

And that is exactly the same as Windows. There is one solution across the whole system and it works together because it is written by the same people and tested together.