Since money and the things it can buy represent something precious and irreplaceable, there is good reason to use deadly force to keep control of something you own. That something that is irreplaceable, is your time. You are born with only so much of it, you traded some of it, or maybe a lot of it, for money to buy goods. By stealing your goods, they are actually taking a part of your life energy. Damn right deadly force is justified. For a sack of marbles no, but for a car or a wallet or purse, yes.
In the state of Washington the rule is you can use deadly force “to prevent a felony”. But, one might spend more money on the legal costs than what the item is worth. Shame to have to think that way, but....