This is just anecdotal:

The first Geek Cruise was the Perl Whirl. This was followed by (among others) a Java one, a Database one, and an XML one.

According to at least one person I know that was on the Perl one and the Java one, the Perl crowd was much more fun and interesting.

My own experience on the Perl Whirl was that the crowd was, indeed, pretty diverse. But the interests you list are probably geek interests (or interests of a particular age group) in general.

If you look at "good beer" for instance, you'll find that many homebrewers and beer judges are computer programmers of one sort or another.

What am I trying to say? I guess just this: since the nature of the Perl jobs tends to be somewhat different from that of the classic "IT" programmer job, Perl will attract somewhat different people. But programmers in general are a distinct group in terms of tastes, hobbies, etc.