Not entirely sure why, but I liked this Myke Merill guy. His point about evil being the absence of good isn't only his, of course. It goes back to St. Augustine, who said the same thing. Think of good and evil as being not so much opposites, as being like points on the absolute temperature scale. At one end is absolute zero deg. K. At the other end are temperatures unimaginably higher. But they're all the same essential quality of thing vibrating (as it were) at different frequencies/amplitudes (f/a). Near the bottom, the f/a is low. Nearer the top, it's great.
The "moral imperative" is just a phrase. Maybe it could be expressed as the "evolutionary" imperative, or the direction one needs to go in if one is to evolve, to progress to higher f/a's of vibration. As one does that, one gets clearer and clearer perspectives; is able to see things more and more as they actually are.
The choice is a free one: to vibrate at a low or high f/a. From lower perspectives, one is concerned with ego; from higher perspectives, one is less concerned with it. At lower levels, rewards can only be material, but the dissatisfaction may be great. At higher levels, such material things as one possesses are seen as incidental, not necessary beyond a certain point; what matters is the perspective one has worked hard for, not justified by desire for material reward, but by a desire for truth. And, as one gets nearer and nearer truth, one's satisfaction increases.
"Bad people" are those vibrating at a low f/a. "Evil" is what they do in an attempt to gain greater satisfaction than they currently have. They aren't irrational, so much as terribly confused about how to increase their satisfaction. Or maybe just terribly lazy. Or both. "Better" people are less confused, less lazy, or both.
What really irks is that the confusion/laziness of "bad" people causes harm to others. But it's harm that, in the grand scheme of things -- if one believes in the immortality of the soul -- can have no permanent effect. Indeed, in some circumstances it might be exactly what is needed for evolution to take place.