Well, look at the critique when Gnome3 came out to replace Gnome2. What pissed people off was exactly that it:
1. Set a certain amount of choices on how the gui should work and
2. Removed a lot of settings, especially those that would have allowed people to reset the things in point 1 to what they liked from Gnome 1&2.
It's one thing for a GUI maker to move the task bar from side to top/bottom for instance, but another to also not allow you to have it back where you "need" it to be. Even when you do want to move defaults (like tmux changing hotkey from screens ctrl-a to ctrl-b) it still is a good idea to allow people to set it back, even if only for a transitional period. Muscle memory takes a while to change for some, and GUIs are not except from that, so if you always had the trashcan to the right, moving it to the left will piss someone off, but not as much as preventing that someone from moving it back again, if that is their preference, perhaps even a preference that your previous versions of the GUIs made for them.
It's one thing for a GUI maker to move the task bar from side to top/bottom for instance, but another to also not allow you to have it back where you "need" it to be. Even when you do want to move defaults (like tmux changing hotkey from screens ctrl-a to ctrl-b) it still is a good idea to allow people to set it back, even if only for a transitional period. Muscle memory takes a while to change for some, and GUIs are not except from that, so if you always had the trashcan to the right, moving it to the left will piss someone off, but not as much as preventing that someone from moving it back again, if that is their preference, perhaps even a preference that your previous versions of the GUIs made for them.