Why do we Americans entrust our entire political system to lawyers?

Why is it that the vast majority of our politicians in elected office are ex-lawyers? I have noticed that holding a J.D. seems to be a unofficial requirement to winning political office is this country. Wouldn't our democracy benefit from a political body that included a much more diversified range of people from all professional backgrounds, including teachers, engineers, scientists, church leaders, professors, artists, etc., in order to draw on their varied experiences in "real world jobs" in making legislative decisions? It just seems odd that while many largely mistrust lawyers and paint them as greedy, conniving, and elitist, but don't seem to have a problem (and sometimes even encourage) electing the same ex-lawyers into positions of power in our country.