Note that Adobe seems intent on being the only provider for complete implementations of Flash. Just take a look at their handling of RTMP.
When they finally released specifications for the protocol, it omitted a description of the RTMPE encryption protocol. Furthermore, the license on the specification forbids people from using the specification to reverse engineer the encryption protocol.
And when the protocol was reverse engineered (which happened before the spec release), they used a bogus DMCA take down notice to get the code deleted from SourceForge.
What do you think they are going to do with Gnash or Swfdec gets to the point where they can play RTMPE streams?