In my opinion, one of the reasons that America is so exceptional is that from the very beginning, the individual is supposed to be more powerful than the government that serves them. Many countries pretend to empower the individual, but in America, the right to bear arms means that power is more than just words.
But, yes, there is a price for that. And crazy people have done some very bad things. If we change the laws in the way the government wants, we are no longer exceptional.
There was a time when crazy people were removed from society. I’m not advocating throwing a net over everyone that says or does something out of the “norms,” but the vast majority of individuals carrying out these acts have had lengthy, well documented histories of serious mental illness.