TK, in Vietnam the Vietcong handed out a few rifles and ammo to villages and advised them that when the Americans approach they are going to kill everyone and level your village. So, when the Americans approached a few pot shots ring out of the village and the GI's unleash hell leveling the village. The next village got the message and has more guns and ammo. The moral is that people don't give up without a fight and your enemy can use those scorched earth tactics to sway the populice against you.
Your tactics could pit the entire population of Iraq against our guys. We'd be on the losing end of that one.