Bottom line is that if everybody is a "priority" than nobody is "priority". The people who control this, e.g. the marketing cookies, aren't the logistics cookies, so we get the more senior and experienced agents handling the problem passengers and delaying the people who believe that the expedited service is important to them.

For what it is worth, at busy airports with short-haul traffic, the entire concept of check-in counters needs to be revised and many carriers are doing it. Self-checking luggage is the simplest thing and 4-5 baggage tag printers can be supervised by one junior staff person. This leaves more highly-trained staff to deal with those people who really do need a staff person.