If a route can go in, it can be removed. There is no 'entitlement' beyond that which we all have, e.g. what Mucci mentioned.
The going in part requires some ethical approach since it involves installing the hardware.
The removal is mere restoration. That's why it is important to do a good job.
Doing it ground up is just style in method, not ethics in method. An ethical result is what one would be after in that case. Again, the goal of restoration being paramount.
Further, to say that someone that can't climb 5.13 can't pull and patch offensive 5.13 routes would be an appeal to elitism that has no grounding in the reason for the removal. Presumably the removal corrects an offense. Having a prerequisite of a certain climbing ability means that only certain climbing abilities are permitted to put up routes.
Under egalitarian and democratic notions, that would be technically called horseshit.