Just as importantly, Apple and Steve learned not to rely on someone else’s technology. PowerPC and all that (when Motorola stopped keeping up with Intel and Apple suffered)
Look at things through this lens and their behavior over the past decade makes a lot of sense.
Flash was the great battery killer. I hated it on laptops. I'd have hated it on phones if it were available. I even hated it on desktops because it made the fans turn up. Sometimes more than a proper 3d native game that used all the hardware you could throw at it.
Of course now we have Javascript and Unity games on the native side so we just changed what screws us up.
but it was replaced with.. nothing. and there is still a gap in that market for novice creators that all the webgl/html5/toolkit-of-the-week has yet to cater towards.
Jobs interest in bad-mouthing it in the early days had more to do with cutting development costs on his side, if flash and adobe is the devil there is no need to spend time and effort developing compatibility layers for it, and it's a chance to wedge the populous towards a solution he can control more closely.
'vulnerabilities' was just the talking point he used to do so.
The reason Flash (and Director before it) was so popular is that it had a very low barrier to entry for creatives.
I still miss Director because of how easy it was to quickly create cross platform apps that could do just about anything.
Flash was crappy, but so what?
The fact that flash was crappy didn't matter to him. If he wasn't artificially prevented by copyright, he could have and would have just wrote his own implementation that wasn't crappy.
The only problem with flash was that Adobe did to him exactly the same thing he did to everyone else. Flash was a proprietary thing that didn't happen to work the way he'd like, and he wasn't allowed to just make his own better version, and so, "This needs to be an open standard!"
That statement doesn't mean he endorsed or preferred or recognized the value and virtue of open standards. All it means is that he was a huge hypocrite who would say anything at any time, and actually do the opposite the instant he can devise a way to.
He only ever recognized a standard when he is the beneficiary of it and there was no physically possible way to get around it, and only until he manages to devise a way to get around it.
One day he says "bicycle for the mind" and that much is absolutely true.
But the next day tries to sell a bicycle that the user can't repair or add a luggage rack, and conveniently declines to acknowledge that a large part of what makes a human with a bicycle so efficient is that the bicycle is simple and user-serviceable in the field and adaptable. The human is more efficient and powerful because they are literally empowered.
The advantage of the wheels turn completely the other way into the disadvantage of a piece of broken machine you have to carry, after you also paid money to aquire it in the first place, when you can't fix it's bent wheel, or add a headlight or a luggage bag or a lower set of gears or fatter tires etc etc to adapt it to your individual slightly different needs.
He said "bicycle for the mind", but never sold a bicycle for the mind once.