I think this is exactly the sort of position that leads to problems later when people find their implicit assumptions don't match with those of others.

I can write perfectly idiomatic code in Perl, using map, grep, simple postconditionals, taking advantage of built in functions that topicalize, knowledge of when items are passed by reference or copy (or a sort of alias), and the code will be very succinct and readable to Perl programmers. Should I forego some of that to make the code more readable to general programmers? Doing so will necessarily make the code slightly less readable to those expecting idiomatic Perl.

I'm not espousing one way over the other, just that it should be thought about with regard to the purpose of the code, who owns it, and who will be looking at it in the future. The exact answer may differ in different situations.