Jenda and ikegami discourage running modules directly. In general, they are right, but:
Just because I (and they, obviously ;-)) don't know a legitimate reason to use modulinos and the like, doesn't mean there is no legitimate reason - and what isn't legitimate for one, might well be for someone else.
Comment on Re: Perl doesn't give error when module is not found 2
Just because I (and they, obviously ;-)) don't know a legitimate reason to use modulinos and the like
Though modulinos are too sneaky/clever for my tastes ("scripts should use modules, not pretend to be modules"),
they do have some well-respected fans, led by their illustrious inventor brian_d_foy,
as described in more detail at modulino References.
My preference is keep my script mainlines as short as is practicable, with all the heavy lifting done in (unit-tested) module/s.