It's a little unpleasant that this method has the effect of moving items too. A tooltip to remind that command click allows remove the shortcut of the toolbar would have been a much better choice. Players wouldn't search how do it, and there's no confusion with dragging items. For sure dragging could work as it is anyway and command click to remove, plus a tooltip to remind it.
In general the game is quite old on this point and under use tooltips.
OMFG 50h played and i didn't know that. It's been driving me nuts. -.-
Thank you!
EDIT: Oh now i know why. It doesn't work. What's command click anyway? Mac? CTRL doesnt' do anything..