I thought he'd be given another shot at it, but I do wonder if his stubbornness in not admitting his mistakes has cost him. The season post-mortem with the board must have been the catalyst for this, otherwise he'd have gone last week. The centre half issues sum it up for me and not bringing Collins back in for the 2nd leg was wrong IMO.
All that said, I'd have given him until Christmas, but I am not surprised in the slightest that he's gone. He's made too many mistakes - the centre half situation, the constant conceding from set-pieces, the repeated small weak midfield.
It is worth sticking to something if you can see the building blocks, but as others have said, this wasn't actually in much evidence from last season. There was no spine to the team, and setting up defensively despite that being the worst part of our squad did not suit the team and made for some excruciating football at home. And all that is consistent with his time at Derby, and we're stuck another division down.
I am sad he didn't achieve more after the promise of last year, but we had the most resources of any club in this division and we have seriously under-performed. We're all sick of this division and football is a results business these days. What we've done today is no more short term than 90% of the rest of the league.
As for replacements, Nigel Adkins would be my preference, knows what he's doing at this level. Warburton second choice.