I think most experienced devs (including those at GNOME) understand this. It's just that on balance they think some changes are worth it. Every developer will make different judgments on that front.
Making a change optional is frequently, though not always, _very_ impractical. Especially without unlimited resources but often even if you did have that.
Everyone knows that people don't like change and that change breaks some things. The question is how to handle that without being CDE or Blackberry or some other technology that was destroyed by the new and different.
Suggesting that change is always or never OK is not a useful guideline for people who need to make real world judgments.