You'd be amazed how big that small niche is. Quite a lot of people like .NET development.

.NET is massive. Just look for job listings. C# gets more money over here in the UK than C++, with there being far far far more jobs using C# and .NET.

Also, just look at how many developer jobs there are in Windows-land versus Linux-land: you hardly ever see Linux development jobs apart from embedded development. Windows is huge.

Most web development/back-end-services/java jobs are technically linux development if C# jobs are windows development right?

Good point! But the job descriptions will never specifically ask for strong Linux skills - they want you to code and upload, and the languages are not tied exclusively to Linux (although I don't know anyone running a real production server with PHP under Windows, so you're right!)

I never said their nice was small right now. I said that MSFT is not guaranteed a place at the Big Person table in every market forever. For example, when's the last time you saw someone using a MSFT mobile device?

.NET & Windows are used in the enterprise space, a lot. If mainframes are still around in enterprises, as a decent market (still worth billions of dollars), I imagine that .NET & Windows will still be around and probably still worth tens if not hundreds of billions of dollars, 20-30-40 years from now.

There's no foreseeable threat to Microsoft in the enterprise, that market is roughly split in 3 between (mostly) cross platform C++, (mostly) cross platform Java and Windows-only .NET (I don't think any enterprise really uses Mono in production). And both C++ and Java predate .NET, so enterprises seem to love .NET to have moved over to it.

Right. The enterprise is one market, but it isn't the only one. Owning it doesn't mean you own anything else. That's my whole point.