Most scripts can benefit from putting the functionality within a module. In that case, you're distributing the module and the script comes along with it. cpan, pod2html, and many others most people take for granted fall into this category.
Benefits include:
Easier to test because you're testing a module
Easier to reuse in many scripts
Easier to subclass for other people
My criteria for good software:
Does it work?
Can someone else come in, make a change, and be reasonably certain no bugs were introduced?