No animal is aggressive for no reason. Animals get aggressive when they feel threatened, and it’s not always clear to us why they’re threatened in certain situations.
But if an animal is consistently aggressive and therefore a danger, it does need to be taken of in some form to ensure it’s no longer a threat.
Also, animals do not have the capacity to understand morals or what is innocent and what is not. Animals know what they are taught by us (if domesticated as pets).