You can argue it, but you'd be wrong.

Flash is a completely separately contained run-time environment that effectively runs inside a box, not respecting anything outside it. Not respecting any of the building blocks of the system it's running on, the browser it's running on and the framework that builds the actual pages. No HTML, no CSS. It's just a completely foreign system set within a box operating under its own rules.

It's like setting a TV into a wall along with brick and mortar and windows and doors. It might be cool sometimes, but it's the odd man out.