Do apps have a responsibility *not* to help users that are temporarily cognitively impaired in many cases? Are there some tasks that should be too awkward to do when distracted / drunk / tired where difficulty in coping with the interface is a warning to the user to modify their behaviour?

In the case of Untappd I think you would probably have to consume an unsafe amount of alcohol to reach the levels of impairment you simulate above. Would it be responsible for the developer to encourage further drinking at that point, even if only by deliberately designing the UI for it?