If you fly the correct POH approach speed in a PA28 and close the throttle fully as you flare, it will land properly.
However, those who fly non-POH 'short field landings' for their own private purposes would indeed need to use power at touchdown, closing the throttle only when the main wheels touch.
We used to fly such an approach in the PA28; however, when we researched the correct speeds in order to standardise, we discovered that there wasn't anything in the POH to give formal guidance - hence we stopped doing it. I think in the Warrior it was something like a 55 KIAS approach with full flap and a lot of power, closing the throttle before touchdown would result in rapid deceleration, a high sink rate and the inevitable 'arrival'. We demo'd that at a safe height, of course!