All standards are influenced by vendors, browse the IETF RFC's -- eg were not for IBM and Cisco BGP would not have come into being. I collaborated in writing a couple of early draft RTF's with engineers from BT, Wellfleet and IBM, at the time I was working for a large bank that was an early adopter of tunnelling TCP/IP through large SNA networks over ATM circuits. Do you think we weren't each looking after our own interests.
I can't see Amazon, Newscorp, or Elsevier in the Membership list - but I do see Apple, Google, Adobe, Hatchette, Springer & Microsoft. Who's not in the list is just as revealing as who is.
I don't have any insight into the workings of the IDPF, but maybe this is another instance of Mrs. Thatcher's TINA theorem
BR