Because this was the thinking many years ago when they thought up foundation. It is one standard size and it kept the bees from drawing out comb for drone brood, but bees found other places to put it. Killing off drones is akin to trying to wipe out the genetic pool of the bees. The drones spread the genetics from place to place little at a time. Without drones around to fertilize young virgin queens you end up more queen failures and a big mess. F6Hawk - Think about it this way, if everyone around you decided to do the same thing and kill off drones, then you had a hive that superseded, your virgin queen would go out, try to mate, find no drones to mate with and finally become a drone layer herself and end up killing off the hive if you didn't go buy a new mated queen, which would get rid of your genetics in that hive all together. This is one reason we DON'T kill off drones.