It is my opinion that just having to ask a judge for a warrant makes law enforcement officers do a lot more work than if they could just invade someone's privacy as a matter of due course. I don't think I've heard of any judges getting fired for issuing too many warrants, but judges occupy a special place in our society: they are people learned enough in the law of the land that we invest in them the power to adjudicate disputes. The assumption is that the judges hold themselves to a higher standard.