I always hear this accusation of people treating politics like sports, but what do you want? It's a FPTP system, which favors entrenching two parties. In order to maintain the backing (funding, importantly) of one of those two parties, candidates can't fall too far out of line. If you can't get your outsider preferred candidate above 50%, considering there is also likely another main-party candidate with significant policy overlap, you get nothing.

If you want to reduce the spectacle, replace FPTP with a better system that eliminates the need for primaries, and get rid of Citizens United. Good luck.