You are dealing with another person who thinks they are too good to stand out on a cold and wet evening.
It could be cold, warm, light, dark, wet, dry, snowy, icy, sunny, foggy, starlit, moonless, mosquito infested, etc. they would not attend.
There would always be an excuse for a person who wanted to just sit and watch others do the work of supporting the troops and celebrating freedom!
I think I reacted so violently because of the teacher angle.
Imagine thinking a display case was important? Would this be a way to "preach to the choir" or provide a place for others to display their opinions in graffiti?
That's my bet! They will have to provide security to stop CodePink types from removing or defacing it.