This is insanity. They're giving away the software, but have put incredible amounts of engineering into making sure nobody can know how it works. The parts where they make money have little to nothing to do with this.
I've stopped paying for skype service because of the features they force me to have on. One of my "final straw" bugs has been opened since 2007. And it's trivial. How much anti-reverse engineering work has gone in since then?
I'm sure I'd pay them again if I could actually do my own build of a skype client with some of the behaviors I don't like modified.