Looking at the objective facts, it's impossible to absolve Jose of blame even if you think it's the players' fault. We consistently come out of the gates playing with zero energy, a lack of focus, and a general lack of intensity - even in derby games and must-win CL ties. This has been happening since Moyes was here.
Looking at the squad now, the holdovers from Moyes are: Young, Fellaini, Mata, Smalling, Jones, De Gea, and Valencia. Of those, Jones rarely plays and De Gea sits in goal all day so he can hardly be part of the intensity problem. That leaves five outfield players, none of them consistent starters anymore (save perhaps Young), who were here when we first started the descent into sluggishness.
Jose has almost entirely re-hauled the starting 11, and we still come out in games looking like we've all passed a couple doobies around in our pre-game huddle. This isn't a situation where one particular party bears the entirety of the blame, but even the most ardent Jose supporters must recognize that with a refresh of our squad we continue to struggle with the same issues that have plagued us since Fergie retired. There may be a lack of quality involved, but the management has been miserable. Look at what a coach like Klopp is doing with players once thought of as talentless workhorses (Milner, Henderson, etc.) and babies fresh from the academy (Alexander-Arnold).
A good coach is able to coax the very best version out of his players. Say what you will about our team's talent ceiling, but it is undeniable that we have not seen any one of our lads play at even 80% of his ceiling on a consistent basis. That's damming in my eyes.