This argument fails to recognize things can always get worse, and that additional embarrassing acts compound embarrassment. Yes, the product on the field is embarrassing. Yes, flying banners asking for coaching/staff/admin changes is also embarrassing. Here's an illustration:
You are walking down a crowded high school hallway, trip on your shoelaces, fall flat on your face in front of the entire school, and start crying (metaphorically, the product on the field). Then, out of nowhere, your mother comes running in help you, yells at the principal for causing her poor baby to fall, yells at you for having your shoelaces untied, and proceeds to spank you in front of your entire school (the banner).
There was a certain level of embarrassment after the first incident, made worse by the second.