The counter argument to this is that the RFC is exceedingly new, and directly from Apple. Microsoft has been using .local in example (and recommending them for production) AD builds for a decade. I see what Apple is going for, and I don't mind the idea, but the practical results are frustrating and pointless.
The approved standard RFC is new but the proposal RFC and the practice of using .local for mDNS, like the convention of using .local for AD, goes back more than a decade. I agree that the whole thing is silly and pointless but it's not clear who "barged in" on whom.