I'm not into pointing fingers, like most Americans these days -- unless it's straight up.
Fans have slogged through a stark difference in Red Sox' offseasons the past half decade. Dombrowski was declarative, deliberate and decisive -- though his pursuit of star power wasn't really that much different than previous Sox GMs. But since Dombro left, there has been a significant change in the type of ballplayers recruited to the big league roster -- and that includes inferior "replacements" for the All-Stars that Boston chose to not keep longterm.
Moon says it started with Kimbrel/Kelly, but it was really evident with Mookie -- and I don't mean the Sox had to immediately go find another Hall of Famer -- but not even an offer to the best OF available: Springer from Connecticut (in retro, Jason Bay wasn't a bad return for Manny; his WAR in his only full Boston year was higher than any of Ramirez' rest of his career)?
The approach from the front office -- most of whom have been around forever -- has been altered, and so has fan expectations... and not in a good way. If it's just a phase ownership is going through, it's been five years now.