'Most people' and the law are not compatible unless it's converted into law. I think robbery and armed assault is pretty darned terrible as well, but being killed for it? We have to uphold the values of society in that killing someone isn't right, and if we lower the bar, then society degenerates.
Sure it's fine saying that here and now if it's you who arent involved, but if you're that guy, you've just had your livelyhood stolen, it might cost you your business, your welfare, anything.
Do you let them go, and risk never seeing them again or getting anything back?
Not to mention the emotional impact/adrenaline of the moment. You clearly don't have time to stop and think things through in the heat of the moment like that, so to punish someone for it seems a little contrived. If he had shot that guy and just injured him, and that led to arrest and for example, taking down of a large robbery gang, then he would be praised.
a life is not worth some jewellery.
Funny, the robber was willing to put his life on the line for this jewellery.