I hope Tiger plays well. The issue here isn't really whether he wins this tournament or not--it's staying relevant and visible. For Tiger to slide in the rankings and drop off the radar means the end of what little endorsement money is coming his way. By competing, he gets face time on camera, maybe a media-friendly interview spot or two (he really needs to be more available and forthcoming with the golfing world's media), and he needs to play well.
If he blows through a few holes, quits, and says nothing, he might as well sit down for the rest of the year and plan a "comeback" next season.