Since you've invoked my name, some clarification on some things that my position on this are not... I would not say you should never use inheritance in Perl.
And I vehemently disagree that "Inheritance is...a primary reason to have an object system in the first place". I think inheritance sucks in some important ways and these are made worse in Perl. And I also think people tend to way over-value inheritance.
So I think one will be happier in the long run if one considers inheritance (of more than just interfaces) to be more of a "last resort" than the feature of OO. This is even more true in Perl since Perl doesn't really have interfaces (much less really supporting inheritance of them) and Perl's clunky OO system makes inheritance even more problematic in general.