"So why shoot them for stealing property that can be insured and replaced?"
Because that is a bald-faced lie. Many people can no longer afford to replace things that are stolen, especially if they have properly carted for them, and they are more than a couple of years old. Many things from our past are no longer produced, and the "improved" versions are anything but. Then, that insurance that is so thoughtfully spoken about costs money, every year, and will never cover the actual cost to replace it in 90% of the cases. First, there's the deductible to contend with, then the depreciation.
Dealing with an insurance company is a hassle, takes time, and never seems to work as they promised.
Now, might I also interject that, in Alabama a comment on your first statement.
"One who is in caught and "convicted" in Alabama for grand larceny of property is NOT given the death penalty."
One who is caught and "convicted" in Alabama for assault and battery, or even homicide, isn't routinely given the death penalty, either. So, the question, then, is "why shoot them, at all"?
I would also note that the dead teenager was a co-conspirator, and was simply in the wrong place at the right time, and collected a bullet. Had she not been involved in the commission of a felony, she wouldn't have been there to be shot and killed, by accident. Sorry, but I cannot in good faith join the whining crowd about her death being so terrible. She made her choice voluntarily, and the result was her death. Plain and simple.