I suspect the answer is money. Well-funded corporations can and do push their fancy, new messaging platforms hard enough to crowd out any emerging open standar

I suspect the answer is money. Well-funded corporations can and do push their fancy, new messaging platforms hard enough to crowd out any emerging open standard, but they certainly have no intention of paying anything more than lip service to the idea of interoperability. They want to own all of this and turn it into cold, hard cash. Who's going to develop the next big, open standard when WhatsApp can turn into billions of dollars?