But I understand (as I said I have worked as wait staff) some folks come in (a big crowd all too often) and tip 10% or less. You are punishing the wait staff because of other lousy customers that makes no sense. If you would ordinarily cough up 25% at dinner for great service you really should do so
I decide how much to tip based upon the service. It is a gratuity. If it is forced upon me it is no longer a gratuity, it is a requirement. I prefer to be generous with my gratuities and to meet the minimum requirement.