It's important to remember that your body can only absorb a certain amount of protein at a time. If your body can only absorb 20 grams of protein an hour, then it's pointless to eat more than that in one sitting. Look up how much you can absorb in an hour and follow that. Otherwise, the excess protein is wasted.
Not true. There may be a limit on absorption, but it is much higher than that. The relevant issue is not what can be absorbed, but what can be utilized. IF (and that if is really the issue here) you could know how much you could utilize at any moment, you could limit your intake to that, and not "waste" any protein. However, that amount is difficult to determine, and no doubt varies from moment to moment, depending on many factors.
Those who are concerned with optimizing their diets want to have at least enough protein available for maximum utilization, so they want to be sure to exceed that amount, whatever it is. That's why they take in so much. And exceeding that amount (despite the myths about kidney damage) is not harmful, so let them eat away.