"My favorite driver is always either the bad guy or the underdog"

Bo Jackson's quote speaks to the concept that people often root for the "bad person" or the "underdog" in any given situation. This could be translated in a variety of methods, but it is most likely that Bo Jackson is describing the idea that individuals often discover themselves drawn to the characters in a story who are not necessarily the "good guys" or the ones who are expected to win. This could be since these characters often have more fascinating stories and more complicated motivations than the "good guys" or the expected winners. It might also be due to the fact that people often relate to the battles of the "bad guy" or the underdog, and they wish to see them succeed versus the chances. Eventually, Bo Jackson's quote speaks to the idea that people frequently find themselves drawn to the characters who are not necessarily the expected winners, which these characters can typically be the most fascinating and inspiring.