For myself, I was expectant also. However, I spotted the brief blurb in the Boston Globe: "Tiger pulls out of the Buick Challenge, claiming mental fatigue."
The more I read, the more it made sense. Tiger Woods was into his fifth week as a professional. In the week leading up to his professional debut, he won an emotionally draining victory at the U.S. Amateurs. Essentially, he has been going non-stop without a break, and he needed to rest.
This was understandable to me. It turns out that professional golfers occasionally withdraw from tournaments, citing health or personal reasons. This is normal.
What made his withdrawal so notorious was the fact that he had a sponsor's exemption to play at this tournment. This is a favor to Tiger, and Tiger's action could be considered a snub to that favor.
More critically, Tiger was scheduled to have a dinner in his honor the evening before the event. He was to have been awarded the Fred Haskins Award, for college player of the year. People attending that dinner paid up to $200 per ticket. This made Tiger an expensive no-show. There were reports that his agents didn't handle the cancellation very gracefully.
In the end, Tiger issued a public statement and sent letters to all the people scheduled to be at this honorary dinner apologizing for what he had done. "I know what I did was wrong, but I had to get out there, too. The scrutiny I received from the media and people in general and playing a lot took its toll on me. I should've withdrawn from the tournament, but gone to the banquet."