Why not build it in pure AS3 instead of a .fla? This means people who don't have access to the Flash IDE or Flex Builder can't do diddly squat with it. Pure AS

Why not build it in pure AS3 instead of a .fla? This means people who don't have access to the Flash IDE or Flex Builder can't do diddly squat with it. Pure AS3 would enable use of the free Flex SDK instead.