Jobs had two stated reasons for the shift. He said Flash was a crash-prone resource hog and that it wasn’t an open standard. To a large extent, the first point is a consequence of the second. Because Flash is proprietary software developed by Adobe, third parties like Apple don’t have access to the source code or permission to change it. That means they can’t fix bugs or to optimize the code for particular devices. They have to rely on Adobe to do these things in a timely manner.
His Holiness Steve Jobs wants access and permission but doesn’t want his customers to have it. Despite the FUD, there isn’t a benefit beyond Apple’s bottom line in denying users this freedom. Communities are more than capable of protecting themselves from software vulnerabilities and can build stable systems; our track record speaks for itself. Jobs can’t claim otherwise, given that key parts of Apple’s software spring from software freedom.