Comment 150 for bug 66566

(In reply to Jesse Peden from comment #138)
> I suppose it is, but it seems to be counter-productive to get users used to
> having it be CMD-Enter for all of these years and then change it out of the
> middle of nowhere. They could have at least added an option to allow people
> to opt out of it.

We must evolve, and on certain things that means also reaching consensus and coherence with the other browsers, so that users can easily find themselves comfortable moving across them (even if just for development, testing, web-compat issues). Unfortunately in some cases this means changing behaviors that have been with us from a long time (I'm here from 11 years, I know well).
If we'd add a pref for each change, in a few years the code would become totally unmanageable. Surely adding one pref here looks like a no-brainer, but if you multiple that by the hundreds of times I heard someone asking for a pref, you can easily see it's not sustainable long term.
Breaking habits and muscle memory is bad, we don't do that often and we try to avoid it, but when an habit hurts a part of our users and it's inconsistent with the rest of the browsers world, we may actually look into it. This was one case, there have been others, there will be others.