Because the government intrinsically cannot practice any sort of ACTUAL judgment. Any rule will be flaunted and abused.
This father had his pistol license revoked — his constitutional rights denied — because his son talked about “threatening” a kid [a bully, even] with a water gun.
When the left says “We don’t want to take away your guns, we just want more regulation”, the right only need look to stories like this to completely and utterly vindicate every iota of their resistance to change.
[Notice, also, that nobody gives a shit about the actual bullying, something that people take with them beyond school and into their professional lives. You can bet some of the workplace mass shootings were against bullies who would have been a schoolplace mass shooting had their ages simply been younger.]