I don't get what the vet is doing either and one UTI with clean urine tests after does not necessitate an rx diet.
If the vet wanted her on something very palatable, I wonder why something like A/D wasn't chosen.
A lot of vets disagree with homecooking, but as long as you are doing it the right way, they need to get over it. There are plenty of vets out there who will support you. Do you remember the name of the last vet that you liked? Have you tried Googling?