>>150804226
You could stop the obvious examples but it's kind of hard to legislate out entirely. They would just be less obvious about it and jump right before the snap from a regular stance and it would be very difficult to determine an intentional jump vs. just a normal offsides penalty
And all things considered it's cheesy but not a hugely advantageous play for the defense. The offense still retains possession and if you do it more than once you give them a free first down. So yeah, you can force a clock stoppage once but you can't just keep spamming it or else the other team just gets five free yards every snap and you still never get the ball back. And after the first two or three the refs would call it a penalty anyway. It's a desperation move with minimal utility