Forking Emacs on such grounds is a symptom of ego malfunction. The proper step (after diplomacy has failed, which it hasn't yet in this instance) is to author an alternate implementation of the feature in Emacs Lisp and publish it.
The easiest way to produce a monkey patch for Emacs which reverts some behavior would be to maintain your own private fork of the repo, where you do a proper job of rebasing, resolving conflicts and validating. Then from that you take the necessary files (all the files that are different from upstream) and produce the hot-load that can be distributed to people. But, totally not a fork, man!
Maybe just to persuade the mainline maintainers?