Man shut the hell up. If THIS is what gives that driver a little light in their day, then so be it. They ain't doing a damn thing to you except hurting your feelings and that is absolutely within your control.

How about you round up all the "professionals" who shit in bags and poor piss down the side of their trucks and leave it all for fuel station attendants to deal with and go open up your own "professionals only" fuel stop. Then you won't have to see someone's blinky sign that ruins your day so badly.