In a word, greed. In a few more words, people failing to understand, tolerate, care for, and stand up for each other, especially people different from them. Gr

In a word, greed. In a few more words, people failing to understand, tolerate, care for, and stand up for each other, especially people different from them. Greed wasn't just invented. Ditto for the rest. A scientific explanation requires that the dependent variable Y be a function of the independent variable X, if X is claimed to be causative. Another thing I dislike about statements like this is that the speaker always comes out smelling like a rose. That may not have been your intention, but there it is.