It was definitely what drew the first blood.
But in fairness, a lot of people were crying for blood, flash had issues all over, and it was a complete security disaster. Apple's decision basically gave everyone the OK to dump on it.
It also happened at a time where the idea of open web was ascendent, MSIE was being actively fought against, and the people involved were out to excise proprietary platforms.
Also all mobile platform flash implementations had been absolutely awful, barely usable battery killer even ignoring that the UI affordances were just not adapted for mobile touchscreen devices.