Though judging by the logic espoused in the tab-close-button bug step one is to move it to about:config and then step two is removing it all together for not being discoverable enough.

yes, but they also change about:config "Preference Names" possibly to confuse users so that they stop messing with settings? for example the preference name for the number of lines scrolled when using the mousewheel used to be "mousewheel.withnokey.numlines", I believe it is now "mousewheel.acceleration.factor" ... I didn't keep track of all the changes, but I am sure that there is many others.