[FourPenguins]

Everything I've ever heard in programming advice is "don't start with .NET." I did start with .NET (thanks to my high school for that one), and the advice is right.
While .NET is a valuable tool for adhoc programming, particularly by non-programmers, it's a sledge hammer where you often need a chisel. Rather than being tailored to what you need, .NET simply gives you everything you might need. Not only is this resource intensive for even the simplest applications, it also leaves you clueless about some of the things that .NET puts in the back-end.
The result is easy to learn, but leaves you without basic coding practices that you'll need later in life.
(This post is mostly about VB.NET. I know that some of it also applies to C#.NET. I don't know about VC.NET, ASP.NET, or any other .NET language, but I think my point holds for .NET in general.)

That said, I know how much our programmers have to know just to write an autonomous mode (their voodoo amazes me), and it may be time for an easier platform. The real question is whether linux would even be easier. Most of the students with linux experience have desktop linux experience. The build of linux that they would find on a FIRST controller would be a whole different world, and they might find that just as difficult to work with as they find the current microcontroller, but as linux is a more complex system, there would be even more opportunity to get lost in it.