I think there are plenty of players who think they can turn any team into a winner, even if they have a long history that says otherwise. They nearly never say they sign for the money, but money is almost always the prime factor.
Even Corey Kluber this year only took the one year for the Yankees because he very likely believes he can turn this into a bigger, better deal next season. A 2 year deal hinders him because he would be 36 next time he hit the market. And a team option becomes worst cae scenario for him, because he either does not get the chance to hit the market again if he is good, or he has a rough year and has to prove himself again...