No no, it is not a matter of Perlmonks being anything else than an English-based website. This is the way it has been set-up and the way it should remain, but ... it does not mean that foreign language posts should be banned or even "tagged" with little "Warning: foreign language post follows" signs.
Suppose an Anonymous Perlmonk out of Inner-Mongolia posts a message in Mongolian. It may very well be that it is not about Perl at all, but maybe a diatribe against his Government or an advertisement for exotic herbs which will increase your reproductive functions (hardly appropriate in a Monastery, I'd say). However, as he is the only Mongolian speaking poster/Monk, his message will have no effect whatsoever on the community. And if there is someone who understands this post and finds it out-of-place, he can alert the Gods to take care of it.
"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law