2 reasons:

#1: It was Tiger
#2: It's what everyone in the US wanted to see

What was so great about it was that you got to see every hole, every shot, every part of the final match that really mattered. If they spread it out equally among the other players, you would see maybe 2 holes of the final group. So, it was in my opinion, the best way to spend 5 hours watching TV I could have imagined. Showing the best player in the world playing the best golf course in the world in the best field of the world in the best tournament "to watch" -- hands down...4 miutes of commercials per every hour? Just golf heaven.

This of course is all subjective based on your region of origin and nationality. I would have loved to see if say, it was Mickel or Els playing against Tiger, but you can't have everything.