WEBF - partly for austere, although I tend to agree with LO on the desirability of operating complex stealth a/c from an austere field, but they also want to get their a/c on their Amphibs. Suspect they don't really care whether its stealthy or not, just whether it'll get airborne off a STOVL run. JSF was the only game in town at the time, hence they got aboard that program. God knows why we did though.
As for RVL the limiter is not the arrestment, it's the ability to go-around if it all goes tits. If the engine is having to spool down and you're nowhere near flying speed, then you're basically knackered. You might be able to keep more thrust on with some form of arrester, but then it would have to be strong, in which case why not go the whole hog, buy Dave Charlie and be open to REAL fallback options, eg F18E or in extremis R****e (there - I've said it), not to mention real MASC and options for real COD/AAR.