Well the discussion started off ok before ending in a rabies infested rant against humanity! Talk about going off the rails!
Anyhow, many people return the trolley so they don't look bad/feel guilty. That doesn't necessarily make them 'good' or 'civilised' and therefore fit into the 'being forced' category through peer pressure. Does that make them 'animals' and 'savages' too?
But the 'test' is peer pressure, no? Which exists permanently in real life so there will always be a portion of people only returning the cart because of that.