I selected Other.
I could teach a semester as to why but I will try and explain my view briefly herein.
When it comes to GUI not a single OS stands out above the rest. They each have a nicety here and there, and they each fail abysmally at the task of providing a true Graphical USER Interface.
I have seen neat things done in Windows, Mac OS, Mac OS X, Amiga OS, BeOS, NextSTEP, KDE, Gnome, IRIX, Solaris, iOS, Android, and Windows Phone OS. But moreover, the best GUIs I've seen where confined to specific applications, and to further support my view these application GUIs used very little of the native OS GUI.
These applications show us we can have better GUIs, so the only conclusion I can draw is that the OS GUI teams choose not to.
