I have a tremendous degree of regard for mcuban, and I think his advice has merit. But I wouldn't say either "trumps" the other. These pithy sayings are handy, but there's a lot of nuance to both of them (IMO) and the devil is in the details.
Should Google have decided not to pursue search because of Altavista, Dogpile, Magellan, Northern Light, Yahoo, and DMOZ? Should Facebook have eschewed social networking because of Friendster, Myspace, Livejournal, etc?
Sometime just being better than the other guys really is enough.