Doesn't it seem like a waste of hooks running em' in tandem? properly rigged eggs and shrimp simply don't need 2 hooks for drift fishing. Bait divers and worms are exceptions but even bait divers work fine with a properly rigged single hook.

I'm assuming your curiosity for the need of 2 hooks is to extend the bite zone when a fish hits. If you feel your single hook isn't rigged to offer maximum bite(chance of barbing in the fishes mouth), drop down a size on your corky or go up a size in your hook. One trick I use is to simply run 2 small beads between the top of the hook and the corky thus your hook is trailing away from the corky for extended "bite". It is every bit as effective as 2 hooks and saves you $$$ if your using high quality, premium hooks.

Just some thoughts.