I know a dozen or so programming and scripting languages but I'm most comfortable coding in PERL and PHP. If I'm trying to develop a product I know I'd want to use my strongest coding skills... and I certainly wouldn't want to learn another programming language.
There is no technical reason why FLASH isn't allowed on the IPhone. Instead it is a marketting decision.. one in a long trend of marketting decisions for companies to keep control of hardware even after they have sold it. I rank Apples decision to actively block FLASH right up their with Sony's decision to remove the Other OS functionality from existing Playstation 3's.
Boojum the brown bunny