FWIW, my team has both written large-scale and high-performance distributed applications using Perl. In fact, we've even done it mostly IN Perl with just tiny bits of C sprinkled here and there. Runs on millions worth of relatively commodity hardware in several data centers across the globe. The only threading going on is at the C level, though.

Your point about these comparisons being dubious (paraphrasing) is perfectly valid, by the way.