Statistics are used everyday by everyone to make decisions, evaluate arguments, and influence people. Calculus is rarely used unless you're in a very mathematical field and could easily be taught in college. Students are also more motivated to learn stats because it has immediate practical implications.
Arthur Benjamin described it best during his TED talk:
http://www.ted.com/talks/arthur_benjamin_s_formula_for_changing_math_edu...
As an engineer, educator and entrepreneur, I know my statistics background is far more valuable than my calculus background in my understanding of the world. As we try digest more and more data, the gap will only widen.
Our misunderstanding of stats is a driving reason for our dysfunctional government and lack of ability to make good decisions.