There is well documented feud that developed years ago between Steve Jobs and Adobe and it has not helped the case for flash on IOS devices. Jobs banned applications, one of which was created by Adobe, that translated flash code so that it would be compatible for IOS. I know of the battery drain arguments but my feeling is give people the choice and let them make the decision rather than lock things down.
At the end of the day, Apple are masters of the closed system and most other systems (Android, Windows, Open Source) are open systems. Each have their pluses and minuses.