If there is a person on your property in a manner that suggests trespassing you don’t want to be playing a guessing game like with the current law of “if the circumstances show equal force” pertaining to you can only legally shoot someone in self-defence if the attacker is armed. If I am inside my home, with my family I don’t want to second guess myself before I go and grab my gun to confront the intruder. I want to act quickly and tactically sound to protect myself and/or my family without the risk if being legally punished for acting in self defence when there is a possible threat to me, and my love ones’ lives. If the counter-argument is the morally challenging one of an unarmed burglar not deserving to get shot, simply don’t break the law - you should have thought about that before deciding to break-in. Before shooting the defender should obviously always act rationally, however and make sure they are acting in a manner that will neutralize the threat, not putting other innocent people in danger.