That's based off a poll asking what is your SINGLE FAVORITE sport. It's not a valid measure of overall popularity. If you really think more people watch soccer and hockey in this country that college basketball, you're crazy. Way more of those NFL fans also follow college basketball./football than ever even look at a soccer game, and outside of the deep South, nobody in great numbers follows auto racing either.
To give this some persepctive, of the 26 most watched sporiting events of 2015, the first 15 were NFL games. #16? The College Football Championship. #17? The NCAA Basketball Final. There were NO auto races, NO hockey games, NO MLB games even. The ONLY soccer game was the WOMEN'S World Cup Final - in 26th place. NO Men's soccer. (Source: Bussiness Insider)