Sure, the example feels a bit over the top, but if you really can't think of an example, then I dare calling you a little short sighted.
It's like saying a Windows user wouldn't want to work at a Node.js shop. What does the dev tech have to do with the OS? And yes, it's a fair comparison, especially since Xamarin.
We're constantly told not all mac users are zealots. If you're a developer who has decided OSX is the best option but isn't religious about it you would probably be willing to work in .net if the rest of that company was good enough.
