GK
The carriers were originally planned around STOVL operations, with a slow shift to allowing the possibility of future catapult operations only appearing late in the day - the RN had NOT been looking for a US-style attack carrier at all!
In MoD it is often difficult to pin down the decision making process. But I know that in April 2003 an ex-Carrier IPT chap came to work for us and he argued until blue in the face that converting to catapults was a "Nil Cost Modification". And this is what the IPT costings assumed. When asked if this was a nett cost (i.e. the cost would be offset by ditching lesser requirements, like aircraft) he said no. So, certainly at that time and for some period before, catapults was an option, but a poorly costed or understood one.
Let's be kind and say there was a variable degree of competence and experience. In December 2000 a similar level of derangement was evident when the IPT was recruiting for their FOAEW team (Sea King AEW Mk7 replacement). They didn't even grant any of the Mk7 team an interview for any post because AEW/Mk7 programme experience was "irrelevant to FOAEW". And you wonder why FOAEW and MASC didn't happen, and they're reinventing the wheel on Crowsnest?