Jobs said it at the keynote when FaceTime was announced. They never managed to follow through, and ultimately had to change the way FaceTime works, because of a lawsuit by a patent troll.
But they did do the work to circumvent the patent. "Patents" can't logically be the reason FaceTime isn't an open standard today. I doubt they ever were. Apple simply realized that FaceTime was an effective sales driver for iOS hardware and wanted to keep that competitive advantage more than they wanted to follow through on Jobs's promise.
The patents forced them to route through their own servers instead of peer to peer. Seems like a logical reason not to make that an open standard to me.
Couldn't they have made it an open standard and required an account with them to communicate with their users? An open standard would have resulted in cross-platform clients.
Correct me if I'm wrong but I've read that they actively shutdown or circumvent projects to create other clients. If they really didn't consider it a strategic asset to push people to iOS I doubt they'd bother with that.
I think there are plausible reasons that could have changed their plans for them. Who knows if they would have actually followed through with the original plan or what their true reasons are. I don't know. That they changed their implementation to relay all video through their servers is known. They said so in court.
I guess they could be saying that they don't want to run servers for competitors to connect to, but under patent law, there's clearly nothing preventing them from doing so.
