It we accept this analogy, the question that arises is - if nature hasn't figured out how to eliminate allergies over millions of years of evolution, what magic do we expect a government to perform?
This is to say that it's a relatively recent problem; one that has not applied selective pressure over the millions of years of evolution you're talking about, but rather the past ~200 years or so. My non-biologist understanding is that you can expect evolution to a relatively good job of adapting to slowly changing conditions over a long period by selecting for the vanishingly small number of mutations that happen to be beneficial.
My citizen understanding of government is that we should expect more of it than that, or it will continue to suck.