Your statement is almost unbelievably ignorant. Even in a state where you have no duty to retreat, the first question that you will be asked after a shooting is what steps you took to avoid the confrontation.
Duty to retreat includes avoiding a confrontation. So, if you do not have a duty to retreat and you are justified in defending your property, the escalation to use of your firearm is also legally justified.
You're right about the civil suit though, that right there is the biggest reason I keep my gun out of situations even where it's legally justified.
As a regional FO, if somoene is breaking into your car and you are not sucking the teets of your parents, you probably have nothing of value, so is it worth it to confront him and escalate it to use of a firearm? Absolutely not. Even though he would deserve 2 to the chest, it's not smart.