Well year some aircraft you have to leave a tad of power on in the landing but certainly not in a PA28 or C172. Some big singles you have to like a PA32 as when you close the throttle the aircraft conciders flying over, like the aircraft I fly there are two models and one has a bit less power than the other and in the lesser powered model when you bring the throttle to flight idle the props are basically in ground fine and flying will cease and especially when we start to flare at about 50 ft or so that can lead to a big crunch. You tipically need about 20% power to help pull through the flare and some small twins are like thet like the C310 and so on. But it is all just a matter of flying the drag curve and closing the throttle at the right time.