One difference I suppose is that in order to create these kinds of Flash applications is that you have to purchase an IDE for the tune of (here in Australia) about $1200 AUD.

Now, that's not too big a deal given computers cost more than that usually but Flash is a very unstable and barely useable IDE. I liken it to spending over a thousand dollars to get slapped in the face.

Disclaimer: I worked with Flash, a lot, for over 3 years. Haven't worked with it in over 4 years, never been happier!