"...Eran Hammer resigned from his role of lead author for the OAuth 2.0 project, withdrew from the IETF working group, and removed his name from the specification in July 2012. Hammer cited a conflict between web and enterprise cultures as his reason for leaving, noting that IETF is a community that is "all about enterprise use cases" and "not capable of simple". "What is now offered is a blueprint for an authorization protocol", he noted, "that is the enterprise way", providing a "whole new frontier to sell consulting services and integration solutions".[28] In comparing OAuth 2.0 with OAuth 1.0, Hammer points out that it has become "more complex, less interoperable, less useful, more incomplete, and most importantly, less secure"...."

"...David Recordon later also removed his name from the specifications for unspecified reasons..."

"...David Harris, author of the email client Pegasus Mail, has criticised OAuth 2.0 as "an absolute dog's breakfast"..."

https://en.wikipedia.org/wiki/OAuth