Apple's main qualm at the time though was "If developers grow dependent on third party development libraries and tools, they can only take advantage of platform enhancements if and when the third party chooses to adopt the new features. We cannot be at the mercy of a third party deciding if and when they will make our enhancements available to our developers."

They've since done a double-take and have accepted games built in Unity and apps built in website-wrapper frameworks (also many of which are proprietary).

Apple had many reasons to want to rightfully kill off Flash. But the thing is, it wasn't all bad.

Note that I do agree however that slow security fixes and Flash causing crashes / consuming lots of CPU are real concerns.