I'm baffled by the response I've gotten in this thread.
I'm not. This is the first I've noticed a "work for me" clause to distinguish your opinions. You started out making what appeared to be a blanket statement about being "not into Perl." You never said, "I would demand a certain level of participation in the community from anyone I chose to extend an employment offer towards." If you had, I'm pretty sure you would have gotten a few more ++'s, a lot less --'s, and, by far more importantly, a completely different set of responses.
I see no problem in how an employer wishes to discern who will make a good employee. I have no issue that you probably would not want me working for you. (Probably for other reasons ;-}) That's your entitlement and your right, as far as I'm concerned. That I think you'd be losing out on a star performer (there's my overblown sense of Hubris again) is not really relevant to your decision process (or maybe it is - I've never been interviewed by you, nor am I likely to be).
Your original statements had no sense of this being an employment issue from the side of the employer. The thread started with the topic being from the other side - cog talking about evaluating potential employers. In that context, it would be like me evaluating how good of a perl employer you would be. And, given your zeal and knowledge of perl, that would be great. But given your ability to get your point across in a socially sensitive manner, I would predict a less-than-ideal working environment, which would not only affect my productivity, but my happiness as a person, and thus the reason why I probably will never be interviewed by you.
I may disagree with the way you evaluate candidates for employment, but I will not (and probably will never) disagree with your right to do so in whatever manner you believe is best for your company. All responses in this thread so far, however, have been without the benefit of the knowledge of your topic because you did nothing to dissuade anyone from believing you were on the original topic.