So why there are no Qt binding, and the previous ones are all dead? And why the Gtk2 and Tk bindings successfully kept alive to now?

That sounds childish to me, but I admit I'm weird

http://search.cpan.org/~cburel/

Distribution                Released
Alien-QtSmoke-4.3.3         15 Dec 2009
Alien-SmokeQt-4.6.0.4       18 Mar 2011
Qt-0.96.0                   19 Mar 2011
Qt4-0.99.0                  14 Feb 2012
[download]

http://search.cpan.org/search?m=dist&q=QT&s=1&n=50