Disarming Bob in Minnesota won't save some kids life in Texas, this is reality and you'll never convince law abiding citizens who pay taxes and follow the law of this. People aren't too keen on being treated as criminals for crimes they never committed.
These school shootings are a 21st century phenomenon, why? Mental illness? Lack of parenting? Both? Other unknown factors? Probably all of them. Regardless, you will never convince people to disarm because a shooting took place 5 States over that has nothing to do with them, ridiculous logic. You will never convince a rape victim she doesn't ACTUALLY need a firearm to protect herself.
You can ponder all you like about how happy you are where you live but reality for some isn't the same as yours. Not everyone lives in a friendly environment. Some desire a form of personal protection, with law enforcement proving how pathetic they really can be.