Who benefits from designing a protocol and network for exchanging multimedia messages that makes it "politically difficult" for new entities to participate, and requires years of work plus owning an "MMSC," which you make sound difficult?
From an Internet point of view, it seems obvious that the value of this protocol and network grows with the number of participating entities. We've understood this since the days of fax machines and Metcalf's law.
I assume the competition here is MIME e-mail with picture/video attachments, which is implemented most places and works pretty well and doesn't take years of work.
If you make your own protocol hard for others to join, you're more likely to lose. (Just as the Information Superhighway and OSI protocols lost in the 1990s to the underdog Internet.)
What are the upsides to doing it this way?