Because he had no options left, this would have had to happen eventually unless the Yankees planned on using him in the majors all season. Getting it over with now probably enabled the Yankees to sneak him through waivers at a time when teams are too busy with their own rosters to be scouring waivers for another outfielder.
Still it was a surprise though. He’s never going to be a starter with the Yankees, but is a solid 4th outfielder type because he can play all three positions, he runs pretty well, and can hit a little bit. I guess with Raul Ibanez and Andruw Jones already in the mix the Yankees didn’t feel like they would carry him to start the season, might as well get this process over with now.