You think it is "understandable" to burn down a building because someone stole your work? If someone did that I would call them "crazy". I definitely see "mental stability" or "mental health" being a root cause here. Rational, healthy people do not respond in that way. Call it "temporary insanity" if you want.
If someone robs a bank, I can understand the motivation: He wants money. If someone punches another, he might want to feel powerful. If someone rapes a woman he wants sex.
And if someones believes that this company stole his money, I can understand his motivations to seek revenge. That does not mean it is right, just or something to look up to. But saying this is completely crazy is a bit naive IMO.
And that is the only arguably victimless crime in your list of 3. A crime can be committed by a rational person (if I don't do this, my child dies), and it can be committed by someone who is not mentally well. I would argue that these, especially the last crime, are all crimes likely to be committed by someone who is not in a stable or healthy state of mind.
Would you say that every crime is either a "rational" crime (if I don't do this, my child dies) or done by someone crazy? If so, I understand the heavy resistance of you and others here.
This is pretty much the definition of crazy, though apparently not self destructive because they survived.
I fully expect the death penalty if he doesn’t prematurely manage to commit suicide though.
By your definition, literally the entire human race is mentally ill. And if that is the case, then the word has no meaning.
I guess it depends on how angry I was?
Would you kill someone who slept with your wife? Regardless of your answer, it would be absurd to call everyone who did crazy.
In fact, courts never do.