Flash was never supported (and thus is being killed) by Apple because Apple likes to have total control over the software that is run on its devices. It is simply protecting its ip.
Flash allows people to run pretty much whatever they like on a given device, be it a media player, game or some other application. Apple doesn't like it because it loses them money. It is about a creating a monopoly, nothing more. It has NOTHING to do with being resource or power hungry.
Microsoft is following suit with its Windows Phone 7.5 OS I believe.