I really can't blame Apple for not allowing Flash on iPhone/iPad/etc... it's really bad on OS X, and an iPhone OS port of flash would be little more than a recompiled version of the Mac flash for a different processor architecture. Adobe seems completely unwilling to make Flash a lean beast, which is unfortunate since THAT would do a lot to attract developers in itself. They're trying to push it as a desktop development suite... if they went whole-hog into optimization and provided a cross-platform alternative to Java that took way less resources than it and didn't have the characteristic Java lag, they'd really have a gold mine. But no, they insist on sitting on their shitty old code.
As proof, under the latest version of OS X (10.6.3) on a 2.66Ghz Core i5 iMac, I opened Safari and viewed a YouTube video page. When playing the lowest resolution available for the video (360p I think) the Flash plugin was eating up about 25% CPU. Memory usage started out at 40MB and gradually creeped up the entire time the plugin was open. That's rather silly, don't you think? In comparison, playing a 480p video in Quicktime or Mplayer with no H.264 acceleration only takes up between 6 and 10% CPU, with memory usage sitting at a solid 25MB. I have to go all the way up to playing a high-bitrate 720p MKV with 5.1 FLAC audio in Quicktime or Mplayer in order to get the same usage that Flash had for a mere shitty-looking 360p movie with shitty audio, and even then QT and Mplayer had set memory usage.
Now this may not matter on a machine which has 400% CPU (that's how OS X sees it) and 4GB+ RAM to work with, but on a mere 600Mhz single-core mobile processor and somewhere in the ballpark of 256MB RAM, it makes a big difference. Going by this usage, a mobile device would be strained to keep moderately complex flash running smoothly, the thing would get hot as hell, and the battery life would be sucked up faster than you can say "Where's my charger?". All in all, it's a terrible user experience, and I can see why Steve doesn't want that having a large presence on the app store. Similarly, having this kick into effect every time you visit a page with a flash banner would not be much better, considering the prevalence of those damned annoying flash ads.