For people not knowing either language, I have the impression that Perl is easy to lear, while Ruby is very easy to learn.
I don't know about Ruby, but I disagree that Perl is easy to learn. Perl has tons and tons of features, quirks, special cases, and its own lexicon of idioms. On top of that, many simple tasks can be done in a diverse set of ways. In my experience as a teacher of both Perl and non-Perl languages, that makes Perl hard to learn. Many languages can be taught in a 3 or 4 day course. If I give a 5 day Perl course, I feel I've barely scratched the language.
Now mind you, I don't think that a language that's hard to learn makes it worse. It's easy to learn how to handle a wheelbarrow, and it's a lot harder to learn to drive an 18 wheeler truck. But that doesn't mean the wheelbarrow is better at hauling.