I hate XML as much as the next guy, but for a phone that can do 20 fps OpenGL scene the cost of parsing XML that is most certainly valid and as used by XMPP is effectively nothing.
It's not just the phone, there is server overhead too, which everyone seems to be ignoring. While XML has a lot of problems, I never said it was the problem with XMPP (although it certainly isn't helping).
I have a life-long passionate hate towards XML, but you have to look at a larger picture to understand why Google is killing XMPP support. It's not the performance, it's not the lack of the protocol elegance. It's the fact that they are building a wall. Facebook got their herd walled and it seems to be working well for them, so it's only natural Google is doing the same. The XMPP was in a way, so it's gotta go.
Other than the unnecessary snark, I don't think we disagree fundamentally. I'm just as annoyed by walled gardens as most people here.
But NIH/control is an unlikely reason for brewing their own protocol. If they simply wanted a wall, they could just disable federation. They've done it before, and it's working for WhatsApp, it's working for Facebook, it's working for Microsoft [1].
G already has a lot of experience with XMPP and it's probably just the engineering reality between what they want to accomplish with Hangouts and what it would take to retrofit XMPP or an existing protocol. Throwing out the baby with the bathwater? Maybe. But it wouldn't be the first time, and won't be the last.
[1] Remember that FBChat, Lync etc are internally proprietary, but they do expose XMPP gateways. Intentionally preventing federation is shitty, but dropping XMPP at the core is not.
I hate XML as much as the next guy, but for a phone that can do 20 fps OpenGL scene the cost of parsing XML that is most certainly valid and as used by XMPP is effectively nothing.