I don't understand why borders have to be considered unspoilt if most of it is the shore soaked with untreated sewage, so with limited allure to the tourists (considering that taking a swim can land you in the hospital).
Not necessarily defending this branch of NIMBYism but contaminated beaches can be cleaned and made usable within a few years if there’s the will and funding to do so. Building energy infrastructure is much more permanent and will alter the landscape for several decades. IMO it’s still worth building the transmission but it’s not logically incoherent or anything to protest it (as it is to protest new infra in existing right-of-ways).