My theory is that it's easy to learn enough Perl to do interesting things. It's easy to learn enough Perl beyond that to do useful things. You don't have to learn about references. You can just get things done.

Perl's Object Orientation is built around references and packages. If you're not familiar with them, OOP will seem alien and scary.

There's also the conceptual leap to consider. Procedural programming is pretty easy. It's like following a recipe or a list of instructions. It takes a little more work to understand things like encapsulation (hiding things that vary) and polymorphism (interpreting a message appropriately). There's less instant gratification.