The only criterion to call the module "not home-grown" is the number of people have chosen it :)

I'll try to explain my idea.
Of course modules (in general) are written by random perl hackers ;) And at the start of the way all CPAN modules are home-grown — and your module too, if it becomes availible to CPAN. But then modules that do popular tasks become popular. I'll call it the community proof. When many peole use the code, they definitely find some odds and bugs. Then the author of the module fixes it — or not. In the second case the usage of the module usually stops.

But if everything is OK, after some cycles of bug finding and fixing the module becomes community-grown. And I prefer community-grown modules to home-grown, of course :)

I think it's obvious :)