Earlier quoted context omitted.
As a person involved in XMPP development for over a decade, I can tell you why. To date, no one ever developed XMPP chat applications as a product, which can be easily deployed and will work consistently on every platform. Client and server developers were always disjointed, working separately from each other. This lead to great inconsistencies in implementations of even such basic functions like adding a contact. Al…
Any comment on the implementation Google did for hangouts/google talk? It seemed like that should have been enough of a push.
When they have dropped Gtalk and went with Hangouts (likely, because of a WhatsApp envy), crippling XMPP compatibility one step at a time, they have claimed the reason for it is that it is 'impossible' to achieve great chat performance with XMPP. Of course, that was a lie. It is quite possible, and we're doing just that.