Why does AIR install only on rpm/deb based Linux distros?

AIR applications are not web applications running outside the browser, but are full-fledged desktop applications with their own windows and access to the filesystem, clipboard and other system resources.
Being desktop applications, they should also integrate well with the system’s package manager (instead of being simply extracted to a directory). On Windows, this corresponds to “Add/Remove Programs”. On Linux, this means the likes of Synaptic or Pirut. This makes it easy for users – since they use the system’s package manager to uninstall other applications, it should be no different for AIR applications. AIR also depends on the package manager for version management of applications (and of the runtime itself) and to ensure that required dependencies are fulfilled.
Since rpm and deb are the most popular package formats, we chose to focus on them. They have been widely adopted, are used in several popular Linux distributions and are not specific to a distro. Who knows which formats will be popular by the time the next version of AIR is released!
Though AIR’s installer is available as a self-extracting executable and AIR applications are distributed as .air files, both of these get installed on the system as native rpm/deb packages. We’re considering alternative distribution formats – If you have an idea or suggestion, please let us know.