No, no it bloody well wasn't. XMPP is a horrible protocol with any number of incompatibilities depending on which set of XEPs your particular implementation supports and which set your clients speak.
There's a reason it never took off, and it has nothing to do with corporate mendacity.
I don't know why more messaging services use XMPP to bootstrap their userbase. It would allow you to switch to a new service, while you could still talk to your friends that haven't moved yet.