The OP was asking for disadvantages of Perl, and I was giving him a common view. An easy thing is only complicated to achieve, which violates a mantra of Perl.

In fact this criticism is so widespread that Larry already changed this design in Perl 6 (almost a decade ago): @ and % default to references and the comma operator is changed.

IMHO that will (sadly) also be the biggest source of confusion for migrating to Perl6.

To be clear: I like flattened list, just shouldn't be the default.