I'd like to say it was to save money, or that it was to produce better quality ammo. But truthfully, it seemed like a another good way to geek out with my guns.
Previously, I got my enjoyment from working on/disassembling/reassembling/repairing/customizing guns, and from building a gun book library and reading anything/everything about guns.
Now I get my jollies mostly from reloading, which I started just a few years ago.
However, I DO appreciate the fact that my old Walther P.38 shoots my reloaded 9mm in nice tight groups. It never shot factory ammo that well, so I always considered it a relatively inaccurate pistol. Reloading proved me wrong on that gun.