Though I agree the have the right to work on whatever they want since it's their shard/server . . .
I don't think they should spend time on this at all since it's a terrible idea that will get 0 usage (for all the reasons multiple people have said) and (as someone else said) would pretty open up the pvp zones to the argument of allowing an opt-out of pvp in those zones, so to me, yes this would be a waste of dev time, from the perspective of a person that plays the game and would want the to work on something else, and sees all the negatives this would bring to the community overall if this were implemented.
Nothing wrong with saying that.