I think the real issue here is airport staffing by the major U.S. airlines. Prior to 9/11, the airlines, as a whole, simply demanded too much from too few agents. This problem has gotten worse since 9/11, as you have fewer employees servicing an increasing number of customers.

When I traveled to OZ last week, I was amazed at the number of check-in stations QF offered at its domestic terminals in SYD and MEL. There was hardly a wait even at the Economy Class counter, and this was during a labor action in MEL. And for the record, QF dedicated a separate check-in position for latecomers (basically they announced that all pax who have not checked in for QF XX should report to position Y).