Because I wouldn't so much say that evolution brings about "better" people or animals... but more along the lines of evolution allows for the gradual emergence of a richly diverse animal kingdom (or plant or fungi kingdom).
I think economic and governmental issues are beyond the scope of this debate. Although one could argue on the grounds of natural selection, and question why nature selected "bad people" as well as "good people," I don't think that supports a creationist argument.
Don't so much personify nature... take a mechanistic viewpoint. When I say nature smiles upon creatures with favorable traits, I'm not referring to an entity that can recognize and distinguish "good" from "bad" traits. What I mean by "nature smiling" is that through this obstacle course of life, those that physically and mentally have what it takes to survive will survive. Whether it be a clever defense from predators, a sensory system designed to detect small prey, or a sophisticated military, those that can gather food and not be eaten will have better odds of success.
Nature doesn't like good people more than bad people; nature is neutral. In fact nature is a noun that could be interpreted as meaning "without interference". Think of the statement, "just step back and let nature take its course."
As for Neanderthal man... the alligator was better suited to accommodate its local environmental conditions. It has few, if any, natural predators. Neanderthal is believed to have had one devastating natural predator... Homosapien. Homosapien survived because it had superior evolutionary traits: motor skills, hand/eye coordination, intelligence, communication, etc. All Neanderthal had was brute strength, which is no match for use of cleverly designed weapons and teamwork abilities brought about by a more advanced system of vocal communications and intelligence.
Nature doesn't "choose" better animals. Fluctuating environmental conditions force animals to either change or die. Those that change will pass those changes to offspring. Neanderthal didn't have what it took to outlive its natural predator, and so you naturaly wouldn't see any of their offspring descendents walking amongst us.