Damon for going to the Yankees, after having been all over the press about how he wouldn't even consider it. And he wasn't the first to leave after the World Series, so not like that was the big factor. Left after the '05 season, didn't he?
Theo's a little heartless sometimes, but had the right idea. Can't overpay to keep the aging stars based on nostalga. Sox made a good offer, but based on his health and playing style, they didn't think they'd get their money's worth if they added the extra year he wanted. He was a shitty LEFT fielder at the end of his deal, imagine if the Sox had had to play him in FENWAY for those last 4 years. We were kinda stocked up on Left field and DH (Ortiz and Manny, then Bay, you may have heard of them?), so that deal wouldn't have worked with the 5th year he was demanding.
Either way, the big part was just going to the Yankees after he talked all kinds of shit about them and how he'd never consider it, evne if they offered him more money. Then he took the extra cash (forget about whether there was confusion about whether he was supposed to offer the Sox a chance to counter the last offer and didn't), cut his hair, and played right into it.
Yankees fans booing Johnny would be pretty shitty fans, honestly. He WANTED to come back, was told NO, and then had to get a job elsewhere. What's to boo him for, from your perspective?