—the danger in having an amount that could be established at a very high level is that the penalty in a commercial contract is unenforceable. If the amount is too high, the courts will not enforce the amount because they will deem this amount a penalty. If the amount is too low, then it has the effect that you just described: it affects a shipper's ability to seek the actual damage amount.
On February 12th, 2013. See this statement in context.