Perhaps if you stopped killing them there might be more about!
I have no idea why you (or others) feel the need to do this to both wasps and bees. I just pick them up and pop them outside, simples. They have no interest in stinging you unless they feel threatened. I have been stung myself on a few occasions, the worst being inside my mouth when I nearly swallowed a wasp (it had sneaked into a can of larger whilst out fishing one day), but that still doesn't put me off them, in fact the very opposite, I find them to be wonderful creatures.