Tk could be considered old-fashioned, but:
- its Text and Canvas are very powerful, and this could outweight many drawbacks
- Tk has Tile, see how it could be used http://vkonovalov.ru/cgi-bin/perl-tcltk-wiki.cgi/41
- I did not adviced you to switch from Tk to an alternative, I just adviced to use Tk differently and more effectively.
On another point, if "old-fashioned" Tk is denied by end-users of software, you can actually use *any* GUI toolkit from Perl.
I, for one, started from using Perl from within C++Builder GUI, but then, step by step, I switched to something more powerful.