He did improve it though, Joey. They finished higher every season he was there, how can that not be improving?
Here he has inherited a squad that wasnt fit and hadnt been playing well for 18 months prior to his arrival, in the 6 months he has been here they haven't really performed much better than the previous 18 months, so surely the players need to be questioned much more than the manager.
I admit i expected much better, but players/teams dont go through two years of bad form, they're genuinely not good enough and Koeman has a bigger job on his hands than anyone expected.