“…as long as proper airspeed is maintained…” What, in the Flare?

Kenneth is correct in stating that you need to approach with the correct airspeed and maintain this until the flare. While flaring the airspeed will decrease, so in that regard you might have a point, but when approaching from a glide with the engine stopped or at idle, you aim to maintain your glide speed until the very last second. If you misjudge and start flaring too soon, you may find yourself approaching a stall or at least a descent with increasing vertical speed, without any option left. Your only way of increasing the speed at such a point would be to lower the nose but you may have run out of room (height-wise and speed-wise) for that as you need to trade altitude to get more speed.