Thoughts on Flash - Steve Jobs.

Performance - At the time Flash did not perform well on mobile devices.

Apple has many proprietary products too. Though the operating system for the iPhone, iPod, and iPad is proprietary, we strongly believe that all standards pertaining to the web should be open. Rather than use Flash, Apple has adopted HTML5, CSS and JavaScript – all open standards."

Apple was adobe's first big customer . Apple invested in Adobe and owned around 20% of the company for many years and had their divergence for many other years when Apple had its near-to-death experience.Today the two companies still work together to serve their jointcreative customers – Mac users buy around half of Adobe’s Creative Suite products ... See more

Videos - Apple devices were not able to play Flash videos, but used H.264.

Security - Flash did not have the best security record at the time in order for apple to add it to its devices.

Adobe claimed to have an open ecosystem and blame Apple's closed ecosystem on the lack of Flash access.

Another point for Jobs was that " Flash was a cross-platform development tool. It is not Adobe’s goal to help developers write the best iPhone, iPod, and iPad apps. It is their goal to help developers write cross-platform apps. And Adobe has been painfully slow to adopt enhancements to Apple’s platforms."

Flash design for PCs with Mice, not devices used with fingers.

Other issues were: Battery power - When using Flash battery power drains faster as opposed to other more efficient technologies such as H.264.