Even perfect societies need human sacrifice

If you follow sinkie blogs and forums like I do, on long commutes in trains and buses, you get the impression that sinkie society is really not too different from the Aztecs and Mayans. Sure, we have nicer buildings and running water and sanitation, but we still believe that certain segments of the population should be "sacrificed", either because they cannot take care of themselves, or they don't believe fervently enough, or they "like" different things. But maybe that's how you make a perfect society?