That's only true for changes of the default behavior, and key bindings
are examples of such a change, at least the way they are proposed.
There was talk about introducing a minor mode which would then be free
to make controversial changes, including key bindings, but no one
stepped forward to write such a mode. Which I think is a pity, given
how easy it should be to do that, and how many problems and
frustrations it could potentially solve.
Once again: significant changes in behavior should generally be
introduced as opt-in features, then the friction will be much lower
and in the long run we could perhaps introduce changes at a faster
pace. Thus, people who insist on making changes in the default
behavior are shooting themselves (and Emacs, if their opinions are
right) in the foot, IME.
Or take indent-tabs-mode, an old pet peeve of mine:
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=20322 I can talk about
contemporary practice, whole-industry polls, threads with personal
opinions anywhere, threads with people expressing confusion about the
current default behavior... but a few people say a change will be
inconvenient -- and it moves nowhere.
indent-tabs-mode is an existing option, so your insistence on turning
it on by default in the face of resistance is ... peculiar. We did
turn it on in some of our sources.