I recognize that getting consensus is hard work, but I don't think creating another encryption-optional protocol and letting vendors duke it over security is going to end well for the users.
HTTP is a deployed protocol with lots of existing
stakeholders, like proxy vendors, network operators,
corporate firewalls and so on. Requiring encryption
with HTTP/2 means that these stakeholders get
disenfranchised.
I'd like to hear the arguments of the potentially-disenfranchised stakeholders first hand. Is it mainly because it makes it harder to sell or use products that allow traffic snooping?