I take the stance that 1 occasional cheeseburger is not going to wreck an otherwise healthy diet, nor put on excess pounds. And the kids like getting a treat at a place where so many other kids eat regularly.

But in support of your stance you will need to show why a cheeseburger is not the best reward.
Here are some arguments, pro & con.

Pro
  • The kids want them.
  • The kids want them.
  • The kids want them.
  • The kids want them.
  • Hard to argue with the fact that the kids want them, so it is a good motivater.


Con:
  • Best not to reward a child with something you don't want them to desire.
  • Not an appropriate reward for the kids who are self-motivated (a book might be better).


I might think of more, but like I said I'm not really excited one way or another over these kinds of things.