we do, if they claim watcher and survive without a result they r going to be more likely scum than not cuz the scum roleblocker wud be blocking elsehwere, unless ur arguing they r abstaining for marginally no benefit
at a bear minimum then we return to where we r and the watcher claiming is not harmful at all, its neutral. if its scum then nobody care if they claimed it. they wont get miscleared for it if they wont use it to give us a scum result, and at the end of the day their play will be what judges them
also why r u assuming watcher/roleblocker combo, and lastly serials usually get rid of watcher, that slot will eventually self.
forcing PoE to claim is at the bear minimum neutral, at most beneficial to town. its not harmful. we dont need roles to win games, we need to attempt to clear PoE.