They got sued heavily for it. They had to completely change the implementation and it became a non-P2P video chat.
No, not true at all. iMessage was never promised, mentioned, or even hinted at being open source. Also, on the FaceTime from they said that the underlying protocols would be submitted to standards bodies as an open standard - that's a completely different things from open source. And the reasons that Apple didn't wind up doing that are well known (lawsuit from patent trolls).
Sounds like you have an axe to grind or only listen to people who do...
Too many fanboys I guess. I would hope the community is more enlightened than that.
Apple did promise to open FaceTime, and was promptly sued – that's why it's not open. AFAIK there was no promise to open iMessage.