As has been noted above, many of the vehicles were bought under UOR funding purely for ops in Afghanistan. While good pieces of kit, they are not intended for wider roles, and often were bought so heavily optimised for HERRICK that they'd be useless in other theatres.
They are also shagged out, well used and have been purchased for a wartime role only.
I'd suggest the ones we want to keep for wider utility will come back. If they don't come back then thats because the British Army was unwilling to make the case to keep them or fund them. That should say something.