Attitudes changed a lot in this country after 9/11. In the '80s and '90s, even calling a plastic soda bottle "a bomb" would not have got anyone that exercised. It was clear to anyone with half a brain that it is incapable of fragmenting or detonating and not much more dangerous than popping a balloon. This was a pretty common form of entertainment and police weren't very interested.
Currently there seems to be a system that groups people based on minor or even innocent incidents together with serious offenders. I'm not sure what use it is to society to both destroy the future of decent citizens and cause inflation in when it comes to serious crimes. You can't keep crying wolf and expect people to be scared every time.
A certain group of very famous people plus a popular social media platform comes to mind?
You are right; the constant state of alert for minor issues tends to numb people when confronted with the real problems.This case was one more step towards the general polarization that is rampant today, with finger wagging and moral lecturing of dissenting groups.
IMO this case illustrates how a mischievous and completely forgettable/forgiveable action is put into law, which gives no other course of action if it reaches levels of hierarchy (the principal, the law enforcement) that have judicial consequences. Although I find it ridiculous, I don't blame the authorities for taking the actions they did. On the other hand, if it was my kid, I would probably have tried to defend him using any means necessary (including a media blow) if he was taken into custody simply for this.
I can't comment on the family decison to move out of the country but, if there were threats to my family due to the excessive exposure, I would probably have moved away as well.