Maybe insane wasn't the best word, "extreme" perhaps. Either way I don't think it's intended as a trope. It just highlights the lengths average ppl have to go and the great cost it requires to make change.
Not sure why you think it's a trope or that the characters aren't presented as intelligent. Whether it's Silverhand, Mr Robot or Black Sails, all those characters are intelligent. Righteousness on the other hand is subjective.
This.
Indeed, extreme is a far better description of Johnny's methods. Johnny isn't insane. In fact, I'd argue he's very sane and acutely aware of the realities of CP's world. Far more than your average Night City resident. He's an extreme product of the world he lives in, but he is far from insane.