I'm not going to disagree, but...we are chemically-driven machines. Gambling triggers addictive releases of pleasure/pain that aren't equivalent to most other forms of entertainment. Most forms of gambling are successful because they are excellent at delivering random reinforcement to players, which is key to many addictive behaviors. But the games themselves are not intrinsically interesting to most people.
DFS takes applies the same principles of gambling and couples it with the most popular sport in the country.