While obtaining fitness is generally a more popular goal than obtaining fame in street racing, I wouldn't call it generally universal; at least not in the US.

Studies have shown that the majority of people in the US get far less exercise, and even move far less than their grandparents did. While there is a sizable minority in the US who engage in regular exercise; I would probably describe Crossfit as a fringe activity here - albeit a currently faddish and loudly marketed one.