Wow this thread really blew up.
@Bass - I'm in comp sci for the same reasons, but I keep my scope a bit smaller. Even a boring line-of-business application is changing the world for a select group of people. Things don't need to be bleeding edge to be effective, and they don't need to alter human history to be valuable.
Is .NET becoming moot? I think so, at least in the way that the desktop OS is becoming moot. The user wants a browser and an app store. Everything else is just details.
Is Angular the answer? I don't think so. It's the JS framework du jour, but check back in 5 years. I'm sure everyone will have moved on to the Next Big Thing (c). Knowing a general purpose language like C# or Java will help a lot more than knowing a specific JS MVC framework.