"Why can people not accept our carriers will be able to provide defence for crisis response shipping or amphibious forces, with F-35B Lightning and Merlin HM2? In any operation with a major need for AAW or ASW capabilities, then you need a carrier."
No-one is arguing about that - what the nay-sayers believe is that any such operation is very very unlikely and if it did brew up then the UK carriers wouldn't be a major contribution - or not for long.
It's 75 years since WW2 and we have had a single police action that required UK carriers - that's a very expensive insurance policy - especially when its bought at the cost of reducing the flexibility to deploy an ever decreasing number of escorts elsewhere across the globe.