I don't think anyone at Adobe is against open-sourcing the whole player; the problem would be relicensing it. It's a massive, hugely complex project, with lots of chunks that were licensed or written by other parties. And the codebase was probably 10-12 years old before anyone even considered the idea of opening anything...

I definitely agree it'd be hugely useful, and wish it would happen, but I kind of doubt we'll ever see it.