Yes it would. Because making it universal enough makes it incredibly verbose and nasty to work with. JSON became popular because it was simpler than Web Services which became popular because it was simpler than CORBA which became popular because it was simpler than just talking over raw sockets using some sort of protocol ... oh, wait.

Actually not having a "universal" spec helps: it forces every provider to give some thought to how to make his API as lean as possible. Hopefully.