Also, people do complain about the implementation of Unity. They complain that its slows down graphics, like all composited interfaces do. They complained that there was "Unredirected Fullscreen Windows" support like KDE and Gnome Shell.
Any complaints about the astetics of the interface is garbage though, its all up to the user to decide if they like that. They might not like it, but it doesn't mean that anyone wants to hear about it.