Regex's predate perl quite substantially. Think grep and friends if nothing else.

Certainly making the perlre library available separate to perl encouraged its widespread use, and lots of others copied or were inspired by it.

"Popularized" doesn't seem like quite the right word though, I don't disagree with the point, but if I shout "Hey everyone let's write regex's" at the office people throw stationary at me, which is not true of other popular things!