Lets just take this to the extreme. If society benefits from fewer people, wouldn't it benefit even more if there were 0 people... oh wait, that won't work . Obviously society benefits from productive citizens. Being productive is the key... not killing off the unwanted.
Lets just take this to the extreme. If society benefits from fewer people, wouldn't it benefit even more if there were 0 people... oh wait, that won't work . Yes, you're right, you do have to be careful about taking arguments to the extreme. Too few people or too many people should be avoided. Your soup shouldn't be too hot or too cold. You should try not to be too fat or too skinny.
Some of us don't have any objection to contraception, used moderately of course. :)