In the end, machines replace people simply because it is cheaper for business. Humans have too many political excuses for suing everyone. And the government control and paperwork involved in dealing with humans is a b*tch. So replace them. Humans are really only good at consumerism anyway. I'd be curious to see which robots in the future get the most richest, and which get the most dangerous. And if they even bother with politics or governments at all like humans seem to hang onto.