Sometimes life carries with it Stupidity Penalties. Here, if you have a pass, forget to put it up, and can show it to the officer on the spot, the Stupidity Penalty is a lecture and a warning. If you can't show it and the ticket's issued, you have to go to court to show it, and the hassle is, essentially, the Stupidity Penalty. If you don't have one, so you can't show the court, you will be paying a big fine and doing quite a lot of community service -- suddenly we have leapt out of Stupid/Forgetful and into the realm of Entitled Meanie.
Helping others avoid Stupidity Penalties is one reason why it is OK around here to say, "Don't forget to put your pass up!" Most people have hang tags that have to be taken down for driving. A reminder comes first, and generally is considered a favor. My response to that is generally, "Didn't I? Oh, thanks!" Or, "No, it is right there, thanks." And if my response is "root....root... oh, dingdangity, I left it in my husband's car/my other bag," well, then, I have to move. And I do. People who have the passes know the rules and the consequences. Others need to learn them.