It could also be because Adobe controls how Flash behaves in the browser. If it suddenly changes some security feature in its Flash player and release it, brows

It could also be because Adobe controls how Flash behaves in the browser. If it suddenly changes some security feature in its Flash player and release it, browsers automatically download the player (users don't really care which version of Flash player they have and usually upgrade to a latest release) and suddenly your content stops working. Fixing it won't be an easy task. You need Flash software to compile the movie and your scripts. Not so with JavaScript and any other open languages. This was one of the reasons why I moved out of Flash/ActionScript world.