And given how strong the tools in Perl are for working with hashes and arrays (grep, map, join, splice/unsplice, shift/unshift, sort, etc.) it really is a pain point.

Not really:

  my $ref  = [qw/foo bar baz/];
  my $ref2 = [map { uc } @$ref]; # [qw/FOO BAR BAZ/]

References, if anything, are just slightly ugly. I could live without non-reference values, however. They're basically useless, but sometimes they make the program more concise.

I think everyone realizes this mistake, however, and Perl6 only has types that behave like references:

  my @foo = split '/', "foo/bar/baz";
  function(@foo, 'hello');

  sub function(@foo, $string){ ... }