There are a few different implementations of SPDY, and a clear use case where it applies. Also, it's a clear standard, made for being used.
What's happening here is that there is a group of very active people that create most of the software we use on the web, and have a use case they want to support. At the same time, there are lots and lots of people that are not as active, with a huge amount of use cases that will be hindered, but since they are not active, they have very little voice.
I've never read it in enough depth to verify those claims, but the response from the standard group is always "then use HTTP 1.1", what is as a non-solution as it gets.
SPDY was great exactly because it was not the standard, it was an extra option, available if everybody agreed to it. Call it HTTP 2, and it will become mandatory in no time. IETF calling it optional won't change a thing.