Part of the answer surely lies in ministers underestimating how difficult it can be to stay on top of your brief when problems arise. One could sense the Conservatives looking at Labour ministers in the past government and thinking: 'This lot keep messing up because they are rubbish; I know I am not rubbish, so I will be fine.'
Did each former Labour minister handle every crisis with aplomb over 13 years? Palpably not. Yet the opposite view - that every rough patch under Labour was simply the result of ministerial bungling - is equally absurd.
Hence, we have seen ministers taking their eyes off the ball and walking right into avoidable cock-ups: chaos over school closures, an aborted forests sell-off and the mire of defence cuts, to name but a few.
But another factor dragging the Government down is the uncanny way that lack of ministerial grip has been mirrored by the Government's post-Andy Coulson comms operation.
Some of the attacks are probably unfair. But creating a muddle over whether the Prime Minister supports a member of the Royal family continuing as a UK trade envoy is more serious. So is leaving the impression that ministers are pointing the finger at each other over the SAS mission to Libya.
It is unremittingly tough at the centre and the learning curve is steep. I remember the panic at being caught off-guard by Gordon Brown at my first PMQs in Downing Street.
Even so, Downing Street will be alarmed at the way in which so many seasoned hacks have taken time out of their busy schedules to tear a strip or two off the post-Coulson operation.
At a time when ministers are getting into trouble with increasing frequency, they know everyone around them needs to be on their mettle.