Oh yea, we have different opinions alright. You don't think people should be able to defend themselves in their own homes, i do. If guns were illegal and someone is murdered in their own home (possibly even someone you love) your stance on the issue pretty much says "sorry, but that's just the way the cookie crumbles". That's cold man.
What sane teacher is going to carry a gun given the massive legal liability that comes with doing so? Imagine if you were a teacher and the next Adam Lanza walks into your school and starts shooting. He's in a classroom full of kids. He doesn't have to worry about where his shots go. He can simply spray the room with bullets. You, on the other hand, have to make the perfect shot(s). You have to do what even a SWAT team or military special forces would be hard pressed to do. You have to take him down without any collateral damage. How likely is that?
Remember last fall at the Empire State Building when two NYPD cops fired 16 rounds to take down one man armed with a .45 pistol? This was just one guy with one very ordinary handgun and he wasn't wearing any body armor and they were shooting him from a distance of only 8 feet. These cops ended up hitting 9 other people in the process. I think 3 were direct hits to others, with the rest being ricochets.
You can expect a lawsuit to be filed against you if any of your shots miss and hit a kid & you can expect that lawsuit to ask for every last cent you have and ever will have.
Let's say you manage to stop him with several well-placed shots, vastly outperforming NYPD. But one of your shots hits & kills little Suzy who was standing behind him. Your shot hit Mr. Bad Guy, but it over-penetrated and hit her in the head. You saved all the other kids in the room, so you're a great hero indeed, but you'll also be a bankrupt hero who'll be spending years trying to defend yourself from the lawsuit sure to come from Suzy's family.
Only police & military get a free pass on collateral damage. As a mere civilian, you're held to a higher standard. You have to achieve perfection, an impossible standard.