You're arguing from a different definition under which nobody but Adobe ever had the possibility to "kill" flash. I doubt there's much disagreement that Apple's refusal of flash on iOS was the most significant factor in its demise. Without it, Adobe would to this day happily rake in the cash.

It's also a good reminder of the positive influence Apple has often had. Remember that "no flash" was the "no Esc" of its time, and that they had to go all-out to defend it (http://www.apple.com/hotnews/thoughts-on-flash/). 6 years later, it stands as one of the rare cases where a proprietary technology was replaced by an open standard.