I think Mozilla is well aware that it can't please all of the people all of the time. Sometimes an option is added to the user interface, sometimes it is hidden on the about:config page, and sometimes there's no option. One issue is that there are automated tests that need to pass before release and every options generates more and more tests to try to avert errors, so the developers try the limit the number of options created.
Is there a particular change that's bothering you?
