I think you are correct to have been looking for weaknesses - it is good to be prepared for questions your audience may ask you based on what they may have heard about Perl.

So if someone does comment on the "line noise" preconception about Perl, you can smile and talk about the TMTOWTDI culture, but then refer to PBP (if you haven't already, do at least glance over it);or if its reputation of being hard to maintain comes up then you can refer to the wealth of very professional support there is available here and elsewhere and mention how there is a strong movement within the Perl community to really raise consciousness about using good engineering principles while working with it.