Wikipedia:The value of countervandalism

Almost every bad-faith action, unless randomly unintentionally benefiting the community, creates a problem that must be solved by someone, one day. This causes the time of good content creators to be spent on reverting bad edits instead, harming the whole community. By undoing vandalism soon after it occurs, recent changes patrollers benefit the community, making everyone else waste less time on doing what patrollers enjoy. Enthusiastic patrollers spend more time on patrolling than they could ever spend on creating content, simply because they like to do the former task even after a long work day.

People who enjoy doing necessary work should not be asked to do something else instead.