And knives. And cars. And fertilizer. And on and on.
By stigmatizing it you are not removing the guns from the hands of crazy people as well. Instead you are harming the vast majority of peaceful crazy people but secluding the worst from treatment to begin with. The problem here is not access to anything to begin with, it is a lack of access to real treatment and coherent means of getting them to it.
Fix that and we MIGHT be able to talk about removing rights. With what we have now, I see nothing more than an appeal to emotion with broad irrelevant assertions. 'So we just live with crazy people having assault rifles' is not a point. It is an unspecific disingenuous statement.