I think you misunderstand the previous post. By "lock up your wheels" lawkd means that you can brake strongly enough to stop the wheel from turning so that the tire starts skidding. And not just the rear wheel.
Her point is that it doesn't do you any good to get stronger brakes if your current brakes are already strong enough to lock up the front wheel while riding at full speed.

The nice thing about dual-pivot brakes' mechanical advantage is that you don't need to tug so hard on the levers to get a certain amount of braking power.