The PoE essentially draws a distinction between our human value judgments about the world and what we would expect from an omnimax human-centric deity. We do not view the world as perfect--or even all that good--and we would expect better from such a deity.
Although it's reasonable to expect a perfect world from an omnimax deity, its necessary to show the distinction only by arguing that the world could, in our judgment, be merely better than it actually is. Consider a world exactly like our own, but that did not have, for instance, cancer of the rectum or bubonic plague. There's no logical problem: There are an infinite number of physical ailments that we already never suffer from; adding one more to the list doesn't seem to pose much of a philosophical problem.
If you want a bigger issue, how about the whole idea of evolution? It's not like evolution is logically necessary, especially for an even ordinarily intelligent being: We human beings did not wait a half-billion years to evolve a unicycle into a Prius, nor to evolve chewing willow bark into heart transplants. It's preposterous to believe that an omnimax deity would be at least six or seven orders of magnitude less efficient than mere human beings.
The only defense against the PoE is to assert that our value judgments about the world are incorrect--that this is indeed, if not "perfect", then the best of all possible worlds. But this view impales the defender on the other horn of the dilemma: If our value judgments are in fact incorrect, why are they incorrect? How can we correct them? If this is in fact the best of all possible worlds, why have value judgments at all? Does it mean anything at all then to call a deity all- or even maximally-"good"?
The most spirited attempt to wriggle from this horn is the Free Will Defense. But this defense ultimately fails for several reasons. It does not even begin to address natural evil (earthquakes, volcanoes, hurricanes, and the aforementioned cancers and diseases). Second, why should we consider "free will" good just because we happen to like it (or at least think we like it)? Third, many of our notions about ethics in general, like imprisoning people for murder, actually restrict this supposed "greater good" of free will.
Most importantly, there's nothing about free which entails that it must actually cause suffering to be valuable. We already cannot exercise any sort of meaningful freedom to "disobey" the laws of physics. Why could free will not, therefore, be further restricted to not be able to cause any sort of physical harm to other people? As the millionaire said to the starlet, we're now arguing over only the price.
The only options besides atheism are these:
- God is not omni-something (or not omni-anything)
- God is not primarily interested in human well-being
- This world is in fact the best of all possible worlds and any value judgment to the contrary is simply false
I don't know about you, but I'm going with atheism.