I'd appreciate ... just explaining what the mind-set is of these people who seem not just to dislike Perl but to actively hate it.

One of the dark sides of being human is that if you get a sufficiently large group of us together, there will often be a designated object of scorn, for reasons real or imagined, but more often imagined. It seems to help a lot of people and a lot of groups to have an enemy. Lacking a real one, an imaginary enemy will get invented.

Applied to Perl, I think it works like this: Programmers who are anxious about their own abilities need to have something to point to which they aren't. For some, it's Visual Basic (as in "Well, I'm not a Visual Basic programmer. Oh yucky poo!"). For many others, the object of scorn is Perl, and not without some good reason. There's a lot of crap Perl out there, and many people have never gotten past the crap. And there's not a lot written about large systems in Perl. Given this, Perl makes an easy target.