First of all, that's not true, but in our society it comes close. We have had stability and peace for so long that almost anything stolen can be replaced. People don't understand that is not always true.
I watched the show Jericho last year and they had an episode where they were afraid armed men were going to enter the town and some people wanted to blow up the main bridge into town to prevent this. It also got met thinking. In that situation (post apocalyptic), that bridge was probably equal to the lives of at least of dozen people. I personally would have recommended that the entire town bottleneck that bridge and fight to the last man (or woman).
My wife disagreed, but I wonder how many other people are capable of seeing how the value of property fluctuates heavily based on where you are. If you are lost in the winter, your coat becomes very valuable and I would fight to the death to keep it, in the summer who cares.