I think the phrase you're referring to is "When all you have is a hammer, everything looks like a nail." I must say that I like your version better, because the original (to me) implies that using only one tool can result in things being built improperly. Your version, however, sounds more to me like "We can do just about anything we want in Perl, and even if it's not the perfect tool for the job, it's still pretty good."

Guildenstern
Negaterd character class uber alles!