Why would this surprise you? Perl continues to improve and is battle tested. More Perl is written today than ever before (that said, much more software in general is written than ever before, and there is no doubt Perl's share has declined). Particularly if you're doing lots of text processing Perl remains a great choice.
These are really not great talks at all. The speaker doesn't seem to actually know much about Perl, and it seems like the flaws he's found have little to do with Perl, and more to do with just writing insecure code.
