There are two major camps of those who criticize Perl: those who know the language well and those who know the language poorly. Their criticisms do not generally overlap. It's gotten to the point where when someone says "I don't like Perl", I usually say "many people don't" because most people who don't like Perl don't know much about the language and didn't bother to learn. They see sigils on the front of variables and say the language looks like line noise. They see examples of Perl from bad programmers and generalize that to all of Perl. They "know" that only strongly typed (whatever the hell that is) languages are worth considering so Perl "must be bad".
Anyone whose thought processes are that simple-minded is someone I don't want working for me. There are plenty of reasons to dislike Perl. The three aforementioned ones aren't in that list.
One issue which amuses me the most, though, is how some people think Perl is so bad but keep mum on the subject of PHP. Most folks with only a passing familiarity of either language would be hard-pressed to tell them apart.
I wonder, though, if part of the problem lies in Perl's power? To really exploit the full richness of the language, you have to know it well. How many will stick with it long enough to get there?