Im not entirely sure, but I guess there are still some ways to abuse this feature. For example: Players will delay defeats and avoid surrenders, which gives them the opportunity to win after the time ran out and the opponent got booted.
I really like the idea of always having 3 minutes set/left on the clock if you are at the end of your boot time. So you can continue playing.
this wont help, when your time runs out, while you are asleep or just unavailable to attend the game.