My legitimate theory is that the better the average quality of life is, the more people value practicality over ideals. As long as you can get up, drive to work, come home, and watch football/play CoD/whatever, people have very little incentive to care. Also we're a bit more sane now. We're a long way off from that Roman guy who made a "no weapons or you get executed" rule, accidentally walked into the forum with a knife, and stabbed himself to death right then and there.