If you have a 50-50 ratio, you're not using modules enough. How's that for guilt!? Think of all that work people have done to hone great modules and you're not even accepting their gift to the community. :) (There are many ways to look at it)

A module is embodied labor. If your point is that more of the labor should be your own, why arbitrarily draw the line at the labor embodied in modules? Perl itself is a major embodyment of labor. So is the C compiler that compiled it. And so is the operating system that its running on. ...and so is the computer you're using.

Use the tools that are there for you. When you find a tool missing of which you're qualified to create, forge it, refine it, and contribute it to the collection. And feel good in knowing that you're moving the process ahead.