I don't think anyone would disagree that generally stealing is wrong and people who do it in general deserve to face consequences. But the consequences should be proportionate to the crime. I don't think anyone deserves to die for petty theft, regardless of circumstances.
It seems like you are suggesting that if someone takes a $50 package off of my front porch, and then I come outside to confront them, and in the altercation this person makes a threatening gesture towards me then I would be within my rights to use lethal force.
That seems like a disproportionate escalation to me.
Anyway I think we just disagree about some of these proportionality issues.
If someone steals something, that doesn't mean they automatically lose all of their rights to life and property simply because in your mind they are now a "criminal".