The knives are out for Alistair Cook - whether due to bias like Shane Warne's never ending nastiness toward Cook or the general muttering from the Boycotts and others. However if you Google the blogs and pundits on Cook you'll see something interesting and telling: although many agree he should go, not one even touches on who should come next - and there's a reason for that - there isn't anyone! As far as Cook goes, the experts do have some validity - England was whitewashed by the Australians this past winter and now loses to Sri Lanka and some of the blame should be placed on Cook's captaincy. However, lets also be fair to Cook - in Australia the team was undone by one man: Mitchel Johnson - his bowling speed, accuracy & aggression is something that we haven't seen for decades and the batsman had no answer to him. had it not been for him, few believe there would have been such a destruction of England, or subsequent rebuilding. The psychological damage to the team was obvious and it was followed by a culling of coaching staff and players on the scale of a South American coup d'état! So against the gritty battlers that are Sri Lanka, England fielded a number of debutantes and much good came from the series despite the loss - maiden centuries, good bowling and determined batting from unexpected quarters - great test cricket in fact, and rubbish teams don't produce that. Anderson's emotion after the 2nd Test loss, and his heroics with the bat, show the passion and dedication the team has.
There is legitimate criticism of Cook's ability to adapt plans - Boycott summed it up (without mentioning either his mum or a stick of rhubarb) by saying Cook had a "plan A and when that failed he had Plan A and if that didn't work he still had plan A". Again, not sure there was any possible plan for Johnson, but this criticism pre-dates the Ashes series. Perhaps more importantly, Cook's batting has fallen apart - 12 tests without a significant contribution, or century - if he weren't skipper, I doubt he'd be selected. Back to the county he would go to get his head together and remind himself how good he is, and how much he loves to bat. Cook opens for England and was someone that could be relied on to put runs on the board more often than not. If your openers can add 150-200 runs collectively, it allows the middle order to bat more freely and places huge pressure on the opposition bowlers. Cook's 20s combined with rotating partners over the past 18 months just don't cut it - this has placed huge pressure on the middle order and lowered England's scores - how long did they go without a significant innings total, even in wins?
So we have a captain who even during happier days was criticized for one dimensional fielding and bowlingcalls, and who now presides over a team that can't win at bingo never mind cricket, and who's own loss of form is reaching biblical proportions. Ok - so fire him - take the pressure off him and let him recover his batting form!!! Ah but this is the problem that no cricket great is addressing - if you do, then what? Who will captain England? Ian Bell seems disinterested and those who know and respect him say he isn't captain material. Prior? Well he is a leader but is at the twilight of his England career; Broad at one time seemed the obvious choice, but bowlers rarely captain for good reasons - they are often injured and out the team, and they face the difficult choice of when to bowl themselves. He also hasn't been especially successful as one day skipper! Were Trott well and in the team then maybe, but he's out and even if he returns, the last thing he's going to need is the pressure of captaincy. So there's no one.
What are we left with? Alistair Cook - captain of England because there is nobody else. Can't be dropped and allowed to return to form because...there's nobody else. ECB could replace the coach, even KP, despite being one of the great batsman playing today, but not the captain. Its not ideal to have a captain by default but it is reality - its why these former cricket greats criticize Cook, piling on the pressure, without ever offering an alternative...there isn't one.