I'd wager most of the issues this season are to do with mentality, which could stem from a number of things. Key injuries, lack of leadership, success fatigue, the Tottenham game (made worse by the CL game having VAR go the other way), Stones, Bernardo, Sterling after Gomez, UEFA malarkey, Liverpool always winning etc. It could have been any of them, all of them, or even something else.
One thing is I really do think is that the media have got to this bunch, there were noises at the end of last season from the players and even management being bothered by the lack of positive press so it's plausible if not expected that the negative press can affect them too.
But we know that when the players have their heads screwed on they're great. Even this season, when our players are switched on and at full pelt they've looked immense. When we're up for the fight, we're as good as anyone.
Most of the players have won the league with us AT LEAST once and so they know what it takes. It just needs a rocket up the arse. When United failed to win the league under Ferguson he made a couple of key signings, reignited the spark, sent the cheque to the referees, and got them back up to standard. Even at the end when they were relatively rubbish. At Chelsea, they historically have a bunch of winners, who always get back to winning ways once a new manager comes in and revitalises them. As a comparison, Tottenham having no history of success has always seen them fall short at the final hurdles.
Just like 16/17, it'll be small fixes that do the most. Get rid of the deadwood, plug the holes (a CB, a pacey left winger, and a 3rd forward), LEARN from the lessons of this season, a bit of tough love, and a reminder that now there's a PL crown to take back. Rodri will be better, our younger players will all be a year older, the past can be put behind us, and we'll have a point to prove. If Pep and the players really want it, and I mean really really want it, then there's no reason we can't bounce back. The only thing is though, they have to really want it. I for one am optimistic.