Also, they advertise Gtk+ as cross-platform which is not completely true. Ever tried setting up a build environment for Gtk+ on windows? I tried, it is a mess. I don't know if windows support has been improved since then, as it was quite a while ago. Windows was a second class citizen for Gtk+ the last time I tried it.
While I like Qt, it also has its fair share of flaws. In my opinion, the largest flaw is that it is not written in C. Why, you ask? it's simple, because the majority of free and open source projects are written in C and they will not introduce any C++ into their project just for the GUI. Also, the Qt specific preprocessor (or whatever it's called?)... do they really need that?
If Qt would have been written in C, the moment it went GPL a lot more free and open source projects would have added a Qt gui next to their Gtk+ gui.
You can easily create C++ bindings for a C project, but it is more complicated the other way around...