No, that is a good question. I wanted one button on the panel that gave me a list of hosts. The panel would only let me add a button for a top-level menu and the menu editor would not allow me to create a new top-level menu (perhaps because I'm not root?). I could have done it using the favorites menu but it would have been at least one menu down.
Of course another (possibly more accurate) answer is that I enjoy re-inventing wheels in Perl:-) I also wanted to take Perl-Gtk for a spin. The result is something that fits my requirement better than a generic menu would have. And it allows me to edit the menu with gvim - the one true editor.