I understand what he's saying, but I don't understand what it would help. The kid still has to decide and that could take a while. And you will still need a deadline for them to make that decision. Unless I'm reading this wrong.
Since it won't happen, it doesn't seem worth arguing for/against, but I actually think it would make the system far more abusive, not less. "Here's my offer. Take all the time you need to decide, but the offer is only good for the next hour. If you don't sign by then, it will be withdrawn. I have a lot of other kids that are ready to sign if you aren't."