Perhaps a non-US spin on this outrageous and heinous act of oppression might give some perspective.
In the vast majority of stores in the vast majority of UK cities, being asked to hand over a bag/rucksack/backpack/bookbag/handbag etc is not very common at all. Are we more trusting or less likely to thieve? Probably not. But we are a little bit more laid back about this sort of thing.
Maybe aborgman can dig up some stats on rates of shoplifting in the UK compared to the US
However, on those occasions when one IS asked to open ones personal bag on entering a shop, I don't know anyone who has ever felt violated or insulted. You just do it. No big deal. The store has their reasons. There may be a momentary "me? A thief? How dare you?"...but it comes and it goes. It is one of several anti-theft measures put in place, like security cameras, tag detectors on exit and security guards (marked and unmarked).
Again, as several posters have referenced, when I check in at an airport, there is a momentary "me? A terrorist? How dare you?"...but it's just a small price to pay to make my flight that little bit safer.