I had similar feeling when tried regular expressions in Tcl, and it is a reason why I am not fluent in Tcl. "regexp" in Tcl is not a strong part: difficult to use and not as fast as Perl's one.

I can't explain strength of Tcl even to myself, but it certainly possesses some wisdom that lacks in Perl: GUI made extremely easy to use there; it is somehow possible in Tcl and impossible in Perl.
In Perl, complexity grows when module grows, whereas Tcl manages things to remain simple to use, somehow, even when behaviour is no more simple. How Tcl does that - I can't understand.

That is why I use Tcl::Tk whenever I use GUI, and I quite often go to pure Tcl when create GUI