I grew up hearing it as "It's a poor craftsman who blames his tools."
REALLY good guys can do great things with a meager set of tools... I've seen guys form body panels with a claw hammer and an old crappy Craftsman screwdriver.
Give an average guy those same tools, or even an above-average guy, and your results are going to ****. And it's not the craftsman's fault, it's the tools.
Now, a good craftsman should invest in the right tools to do the job. If he doesn't have the right tools to do the job, that says more about him than it does his tools.
So I believe it may, in fact, be a poor craftsman who blames his tools, but a good craftsman has the right tools to begin with.
-Brad