Well,

Adobe claimed that Apple was stopping them from supporting Flash on the original iPhone. When Adobe did finally get Flash (barely) running on Android. It required 1GB of RAM and 1Ghz CPU. The original iPhone had a 400Mhz CPU and 128Mb of RAM.

Adobe was late shipping Flash for the Motorola Xoom. Motorola touted being able to use Flash as a feature over the iPad. Leaving it in the unfortunate situation that you couldn’t even visit the Xoom marketing page running Flash from a Xoom for the first six months.

Adobe could never get Flash working on mobile well.

EDIT: It wasn’t until the iPhone 5 introduced 5 years later in 2012 that there was an iPhone that could have met Adobe’s specs for Flash.