Misery defines the human condition. Why? Because everything is relative. Without refrence points nothing makes sense. Walk down a short hypothetical road with me. Imagine a universe where the physical laws were altered so that angles were impossible. In a world of curves, the word 'curve' would have no meaning since that is all there is. Everything is curved. It's a little like trying to describe darkness to someone blind from birth. Without sorrow, joy is meaningless. Heaven, in essence, needs a hell. The existence of unpleasantness affords us the ability to choose a direction to channel our efforts toward; the opposite one, usually.
For this reason, trying to get rid of undesirables is usually either futile or counter productive as our preferences are often somehow inextricably intertwined with the things we would rather do without. Sickle cell anemia is a genetic disease that is eventually fatal in its relatively rare homozygous form but confers protection from malaria in the more common heterozygous combination. Important, considering the fact that malaria kills thousands of people annually in regions where it is endemic. Most people would rid society of schizophrenia in an instant if they could yet the link between emotional lability and exceptional intelligence is undeniable. Evidently, evolution thinks the benefits of an Albert Einstein outweigh the risk of an occasional marabout.
Apparently, good needs evil and vice versa thus preferring one over the other should be a matter of choice and not a foregone conclusion. While we fill up our jails with tons of inmates, locking away unknown potential, their very existence a testimony to society's failure, an unattainable Utopia remains the goal leaving society open to nihlistic attack. The poor, the hungry will always be with us, crime will remain a problem. Misery is an integral part of the human condition. Sorry John Milton, but it's a little hard to lose something that can't be obtained in the first place.