We have not done that and if we did there would be nothing left of that region, isis is alive because they are hiding amongst the civilians shaving their beards and removing their uniforms to blend in with the civilian population to evade airstrikes. If all civilians where gone it would not take long at all to wipe them out.
But we know better then that so we dont just bomb whatever we like as we like to keep the civilians death toll as low as possible.
If this was WW2 they would have leveled entire cities with civilians and everything, we dont do that anymore.
Civilians death's is at a all time low.