Earlier quoted context omitted.
If you want to demand perfection, then Clojure isn't going to meet your standards (what would?). The issue here is that, based on the way they (particularly Rich) talk, we can expect they will not do Bloody Stupid things like the old Python 2->3 changeover. Things like big, breaking changes that require architectural changes to keep current, or break all the available tutorials. If the problem can be fixed with a mac…
You don't think a breaking change to + is any more significant than a breaking change to some other part of the language?
It is a breaking change, that sort of change could introduce bugs into existing codebases. If that matters, you can't upgrade your Clojure version without careful change management anyway.
It isn't like reduce is being depreciated or something. I don't need to change how I think about the language.