Why are there so many different clients ands services and none of them really work together. oh sure they chirp about interoperability or supporting ALL the major formats in one client but in the end its lip service. Its the same reasons there are hundred versions of Linux. The big players want it all to themselves and actively subvert interoperability while denying it. The little guys are constantly chasing the changes. its all about control, controlling you as an asset.
The old game of win win cooperation we all played in school or some seminar somewhere was always "won" by the first to screw the other guys. That's the real lesson... in "win win" everyone is equal and there's not a winner. In life there are winners and everyone else. Someone is always going to break the contract to gain the upper hand, they just can't resist.
Try BB Messenger... I think they are on all platforms now... I guess it won't be long before someone trips them again.