We already have those two different sets of people happily using Perl 5. I don't see how Perl 6 is going to be much different on that subject.

As for PL/I, it might actually have succeeded had it been an open source language. But PL/I was too complicated to reimplement in an age where reimplemention was the only way to port it.

Not that I like PL/I all that much. As far as I know, Perl only borrowed one feature consciously from PL/I, which is the ability to iterate over a list of values. In many respects PL/I was not a well-integrated language, and it also didn't have the benefit of several decades of language research to draw on. PL/I did most things in an almost right way, from a modern perspective.