The combination of carriers and JSF together represent a massive investment (even ignoring the massive support that a CBG requires) - but one which will give us the ability to deploy only a relatively modest air wing at relatively modest speed and huge expense.
It will only be affordable via a most unlikely hike in defence spending, or by dramatic cuts to other, less exciting but more useful capability areas.
As such, spending on carriers unbalances our forces, and makes them less useful.
Call me cynical (and though I'd kill to be exposed to the informed debate that goes on there), but it doesn't surprise me that the distinguished students at Shrivenham largely support the policy that they'll be expected to implement in their subsequent careers, and it certainly doesn't surprise me that there isn't too much intra-service bickering and argument (on a single service basis, criticising another service's pet programme, and especially one to which our political masters are so firmly committed).
I've never heard a senior officer publicly criticise PFIs - the best anyone's managed having been a vaguely apologetic, mildly regretful, even slightly embarrassed admission that "in other circumstances...."
Nor does the record of half stars and one stars standing up against the way in which 'Smart' has been distorted and twisted to cover a risk averse shuffling off of all support to a monopolistic and monolithic BAE in a succession of DA mods and DA upgrades and an orgy of availability based support contracting. The most distinguished exception to the rule of craven collaboration soon found himself losing his job as the head of his IPT......
So the fact (?) that Army and Air Force students at the Joint Services Command and Staff College are in agreement as to the usefulness and need for carriers does not entirely surprise me.....