VB.Net is my mother tounge. I have made several large to medium sized applications in VB, so I am very familiar with the syntax, however, because VB is more focused on components and UI, it's not very suited for game programming.
One example is, I often use a lot of try catch statements and use a lot of extra code to make sure that it is completely bug free, no matter what the user may do. The user will not mind if it takes 0.5 seconds to run a function.
However, when working with Flash and game programming, if it takes 0.5 seconds per frame, and your game is 25 frames per second, you are in big trouble. (Actually, I am working a way around that)
I hate AS in many other ways, however, "When in Rome, do as the Romans do." I guess I'll have to live with AS's flaws just to be able to work in Flash.
Flash is more made for game programming, and (I forgot exactly what percent) most browsers have Flash, so you reach a wider audience. So now I'm using flash for non-Windows development.