I learned programming in BASIC, in 1981, then spent some years with Turbo Pascal, HyperCard, and eventually VB. I spent upwards of a decade with VB before switching to Python.
I'd have a couple problems with VB as a teaching language. First, there's the business of building GUI's and navigating the project structure. These are not the basics of programming, and are layers of abstraction that obscure the underlying code.
Second, even if there's a free version, it's an enormous bloated download, and only runs on Windows. Python can run on any reasonably modern computer, including the Raspberry Pi and its ilk.
Third, Python is more "cool" right now, meaning that there is a lot more interesting code and projects being shared and discussed online. I actually consider this to be an advantage for my own use of Python at my day job.
Now I think both groups of students will come away with a decent grounding. Those who get into programming will learn more than one language, and I'll bet that there's little correlation between who's a good programmer and what language they started with.