Because every other sacking we’ve made has happened when top 4 becomes either literally impossible (in the case of LVG and Moyes) or practically impossible (in the case of Mouriniho). Despite the fact we all knew in the case of all 3 of those managers that their time was up.
Given the run of games we have coming up, our position in the coming weeks will likely be just as bad as it was when Mourinho was sacked. We're likely to dip into the bottom half in the coming weeks. We're only an Atalanta win away from being in big trouble of qualifying from our CL group again too.
When we sacked Mourinho we were 6th in the table, it was on the back of a run of 2 wins in 8 games in all competitions, similar numbers to the kind we post now. We were further away from the top and top 4, but that was further into the season too. By the end of November we're very likely to be further away than we currently are given our fixtures.
During the last international break there was briefings about how the board thought we were doing fine, on the same points as Man City, 1 behind Liverpool, 2 behind Chelsea. By the next international break, all those gaps will probably be double digits.