For me it was the sacking of Poch. The previous 15 years we were slowly trying to create an identity again. We had Jol, Redknapp and the Poch. These guys did 3, 4 and 5 years respectively and moved us huge steps forward. In between we tried the pragmatic crap, which inevitably failed but then we go back to a more balanced, slightly more attacking way of playing, with hard work and great player management. This helped us get a good blend of players in which Poch almost turned into English and European champions. The approach worked so we ripped up that playbook to again.
After Poch, as per the trends of the previous managers, we went pragmatic again. But then we went pragmatic again. And then we went pragmatic again. And then we went full on all out attack. And then we went pragmatic again.
Now here is the problem with this approach.... Our squad blend and transfer strategy doesn't match. The players don't suit an attacking manager and the crazy thing is they don't suit a pragmatic manager. Literally, only Danso, Solanke, and Palinha are those players. All the rest want the ball, which is great, but none of them were bought for being game changing attackers.
Our squad suits nobody, except maybe a more balanced manager. So we go and get Tudor in to play 7 defensive players and 3 attackers.
We threw away our philosophy that was beginning to work again in the hope for trophies, and now we staring at relegation. It's like being back in the Sugar years - no football plan.