Lets start with this ...
"The Rails core team does seem to treat the project as if it’s a personal playground"
This was said more in frustration with the coffeescript/sass decision than any real belief that it really was the case.
I understand it may be hurtful and disparaging of the amazing effort that the Rails core team has dedicated to making Rails fantastic, and I apologize unreservedly.
With respect to outlining the changes (prototype to jquery etc), I'm not complaining about the changes per se (because I like most of them), what I'm complaining about is the pace of the changes.
Something as major as the asset pipelining feature (where you move assets out of the public folder and into the app folder), for example, seems big enough that it should be a 3.2 release not the next release after an already major change in 3.0.
See what I'm saying?
I haven't worked on the Rails core, so this can be taken with a pinch of salt, but I feel like it would be a good idea to adopt the Intel tick tock refresh style of cpu releases http://en.wikipedia.org/wiki/Intel_Tick-Tock, where major releases come out on the 'tock' and are refined on the 'tick'. That would work well for Rails releases, giving major releases enough time to settle into the Rails consciousness before the next set of changes comes down.
It was great to get a thorough explanation of the rationalization behind the decisions that have been made recently, it would be awesome to see that increase in frequency.
I just want to thank the Rails team for all the hard work and have them understand that while I may argue hard for what I believe, that I have nothing but the highest regard for them.