I, for one, think its not good to recommend Tcl::Tk to novices, because this approach requires deeper knowledge on what is happening, and one should be prepared to unexpected

But I don't understand your argumentation that "Tcl is not Perl" as drawback.
Its quite common to use external library of something, even if that library is not Perl.
Why the limitation?

just for the record, Ruby+Tk, Python+Tk, Perl+Gtk2, etc, etc all use external non-perl libraries.