Jacoby Ellsbury has gotten himself into a fucked up situation by going to the Yankees. By going for the big money, Ellsbury (who will now, and forever, be known as "Ell$") has placed himself in a position where there's a good chance he'll tarnish his entire career. Here are four reasons why:
1) When the Yankees give you a big contract, they expect results - not just individual results, but world championships. But the Yankees are a total shitshow right now. Mariano is gone, Pettitte is gone, Jeter will be gone soon, nobody knows what's happening to A-Roid, there's a huge hole at second base if they can't pony up $200+ million for Cano; Sabathia and Teixeria look like they're declining, and the rest of the team sucks. By signing Ell$ and McCann, the Yankees sacrificed their first two picks in the 2014 draft - so getting prospects to come to the rescue will be a challenge. And if the Yankees have $100+ - $200+ million commitments to Ells$, A-Roid and Cano, then spending money to build right now will also be difficult.
In short: the Yankees are in quite a bind, and they have to feed a relentless fanbase. Blaming Ell$ for the Yankees' future failures is unfair, but NYC isn't known for being "fair." Ell$ willingly placed himself in this situation, so he'll have to reap it.
2) Ell$'s game primarily consists of being a speedster on the basepaths. Right now, he's the best leadoff hitter in baseball - but he's 30. Speed declines with age, so even if he has injury free seasons from now until the end of his contract (assuming the Yankees exercise their 8th year option on him), he'll be 39 with his speed declining each year. Elite sluggers like David Ortiz are able to weather the effects of age and still play at a high level, but speedsters cannot do this. So Ell$ is already setup to fail.
3) And Ell$ has an injury history. Avoiding injuries as he ages is something even the best of players have trouble doing. The first time Ell$ hits the disabled list, he is going to feel the hatred of the rabid Yankees fan base.
4) By going for the money, Ell$ burned all of his good will in Boston.
Considering the situation Ell$ has placed himself in - possibly audacious bad press, hated by fans, little possibility of earning another World Series ring - how will this look on Ell$'s resume for Cooperstown?
That resume would have looked a lot better if Ell$ took a hometown discount to continue playing for the Red Sox. Ortiz took a hometown discount, made it to another World Series, and he not only earned another ring but he placed himself in the "Best Postseason Hitter Ever" argument. Pedroia took the hometown discount and got himself a second ring. Both players have earned the love of the Boston fan base, have (or, almost in Ortiz's case, has had) secure careers, and all of this will look favorably upon them five years after each of them retire and find themselves on the ballot for Cooperstown.
Ell$ went for the money, but I doubt he comprehends the magnitude of his decision. Two decades from now, if he's a middling HOF candidate with little chance of being enshrined, I hope Ell$ is still enjoying all $153 million the Yankees paid to buy off his potential immortality.