There seem to be several questions here.
1) Do we need carriers in order to have balanced, capable forces which fully meet Britain's strategic/geopolitical/military needs?
2) If economies have to be made, should carriers be a higher priority than land-based air?
3) If we do need carriers, long term, would it be acceptable to have a longer 'capability holiday' than already looks likely? (Remember that Harrier can't go on past 2016/17 without major expenditure - new rear fuselages, etc. and JSF can't be in squadron service until 2018....)
Even if you believe that the answers to the first two questions are "yes" and "yes", it may still be that withdrawing CVS and Harrier now would be a sensible way of easing pressure on an overstretched and overstressed defence budget. Is Harrier likely to be needed to deliver effect again before it is scheduled to retire? When you're not involved in 'cat and trap' type carrier aviation, do you need to maintain a cadre of current operating experience, or is it possible, with STOVL aircraft, to work up a capability again fairly quickly - especially if you've been clever with exchange tours....?
Unless you're going to say that actually we can afford to do everything, and that we're no more than eye blink away from massive tax rises being electorally popular.....
For me, the answers are no, no and of course.