I can't find the specific justifications but I believe it's all described in the GNOME HIG: http://library.gnome.org/devel/hig-book/ http://library.gnome.org/de

I can't find the specific justifications but I believe it's all described in the GNOME HIG: http://library.gnome.org/devel/hig-book/ http://library.gnome.org/devel/hig-book/ Not to say it's necessarily correct, but if you really want to dig into their reasoning, that's where it is.