I agree - it is a sad state of affairs. In my opinion, 'zero-tolerance' policies like this one do little to serve the student population.
It's one thing to threaten someone with a gun-shaped hand - implying that when able, you will shoot them - and it's something else entirely when that hand shape is used for meaningful communication. Unfortunately, the zero-tolerance policies of our public schools don't allow teachers and administrators to consider that.
So you have stated that you understand the reason for the school's position. I asked, do you agree with it?
(By the way, I just read that the school has reversed its position - the boy will not be required to change his name-sign).

What is the point of rules that are not enforced?