Ted Neward has written an article on the problems of scaling up projects based on dynamic languages:
While a dynamic language will usually take some kind of performance and memory hit when running on top of VMs that were designed for statically-typed languages, work on the DLR and the MLVM, as well as enhancements to the underlying platform that will be more beneficial to these dynamic language scenarios, will reduce that. Parrot may change that in time, but right now it sits at a 0.5 release and doesn't seem to be making huge inroads into reaching a 1.0 release that will be attractive to anyone outside of the "bleeding-edge" crowd.
Alas, he has to end with "Perl just sucks, period." Even as we work forward with Parrot and Perl 6, the continued public perception of Perl doesn't change. :-(