"You have to drink milk because the baby can't eat steak?"
Quoting a lesser known Vonnegut sci-fi work about self-handicapping?
Attempting to try to get the point you are making, you are saying why should you be forced to give up your AR-15 with 30 round clips that you love so much because someone else used their AR-15 with 30 round clips to shoot up a bunch of innocents in cold blood? Is that what you're saying?
A gun is not a hammer. A gun is not a screwdriver. A gun is an instrument designed for the specific purpose of killing, injuring or simulating killing/injuring. Guns may have their place, but they are hardly an ordinary tool and because of their intended deadly design, they must be subject to higher scrutiny and regulation than your ordinary tools. And the people who want access to them need to be subject to higher regulation and scrutiny because of what guns are specifically designed to do.
Here's the harsh reality. You are capable of becoming mentally ill, or snapping in anger. I am capable of the same. We all are. Stop trying to claim that mental illess is a finite condition that only affects certain people out there in the ether.
Personally, I'm all for mental evaluations if one wishes to use and purchase a gun, and continued periodic evaluations if one wishes to continue to use and purchase a gun. If that's not politically feasible, at least do something as they do in Canada and require rigourous safety courses before being able to possess a gun.
And get rid of the damn maximum capacity clips. There's no reason any civilian needs them. None.