In http://www.apple.com/hotnews/thoughts-on-flash/ writes about the reasons Flash is not allowed on the iPhone and iPad. My 0.02 fiat money's worth is that I see Job's point about Flash not being touch sensitive and having been designed for last-generation devices, and Flash not being appropriate for apps.
I recall the evangelistic tone to the Human Interface guide of the first Macintoshes. The big deal was consistency and economy of motion. Apple has done a great job on the user interface of its devices since then. Now, think about Flash plug-ins in web browsers. When one comes upon a Flash element on a web site, there is no telling what the user interface might be. Consistency is not in Flash'es vocabulary.
Yes it's a pain to a web developer knowing that if I put Flash into a web site, mobile users will not be able to use it. On the other hand, I would rather see Apple in complete control of the stack of software yielding the user interface of my iDevices.
I watched the WallStreet Journal interview with Adobe CEO Shantanu Narayen and sure he has the Flash ecosystem to defend. His retort about Mac OS should be fixed if Flash causes crashes was a cheap shot but it is somewhat revealing. Change your operating system and your user interface to accommodate my software. I side with Jobs and would rather use the new HTML5 standard on my web sites that would be viewable on iPhones and iPads.