A number of things IMO:
The board, Kenwright and co. Fortress Sports fund farce, stadium failures including the infamous Kirkby debacle, a sense of settling for second/third best. Disingenuous use of his media circle when criticism came "Be careful what you wish for" "Don't want to be a Leeds or Portsmouth" which no Evertonian wanted, they wanted better leadership at the top than you, simple as that. Kenwright, Woods and Elstone are still there. Moshiri, not that impressed, seems to talk nonsensical at times, the Steve Walsh situation. Deflating.
Managers:
Moyes developed a big ego in his later years, no sense of what the club was hoping to do long term between club and fans , except a "knife to a gun fight" attitude which he infamously admitted anyway. No trophies, the one chance to step up after doing well to finish fourth in 2005 wasn't taken , pretty much summed it all up.
Martinez: First season, it was some of the best football I had seen Everton play for a long time. A good mixture of a solid base, with pace and keeping the ball with purpose and not just for the sake of it. As time went on the team lost that and developed into a side that could still be a threat but was weaker everywhere else. Some abysmal performances including two heavy defeats at Anfield, the last one even resulting in the clubs official site and social media accounts saying nothing or providing reaction for nearly 24 hours after the final whistle. Should of been dismissed earlier, instead was kept on and fans became more demoralised. No silverware.
Koeman: Egotistical, distant. A superb player on his day, he started off well, particularly with some fans who found his stern comments after games refreshing after the Martinez era. Deteriorated not long after, fans disliked him, performances were inconsistent. Managed a 7th place finish, nothing terrible but nothing to brag about on the whole. This season...well...don't have to say much there. Dismissed, no silverware but can play golf when he wants.
The fans: Atmosphere has detoriated at Goodison. Every fan base has its moan no matter whatbbunch,we are no different. I don't believe that is most blues at heart . I could be very wrong here but from my experience I get the impression a part of the reason for the atmosphere is due to how we have been over the years, a one step forward and two or three back routine which I think many people would be fed up of eventually and this season has hit it home more than ever. It feels monotonous and that is bound to affect a person at some point. I will go back to the board, the defense of the board particularly in
Moyes later years..the things that were said, it was like some fans were reading off a script sheet. "Don't want to be a Leeds, a Venkys" etc etc. What Blue would want us to be like that?? It's the hivemind mentality of "it could be worse" and not "this could be better" that period...I don't think I've felt the same about Everton since and I know a few personally who have said the same.
Players: The better players move on. With us, most of the better players haven't been successful here in terms of silverware, they leave to attain it elsewhere or at least play CL football on a regular basis. Some players have been decent, some have crap attitudes, others don't. The one big positive I can take from this summer is the signing of Pickford, has his faults but he could be a real top class keeper as he matures. I'm hoping things change eventually, that he's one of many players in the future that manages to achieve success here, break the cycle, move on with a few winners medals rather than look to get that first major one elsewhere.