I don't understand how a failing stamp for a campfire is good for the interviewee. It signals that they weren't good enough to get hired. Why would they want to parade that around?
B.A. Political Science, Bangalore University (failed)
Everyone will have some successful stamps, and they accrue over time giving better signal. Hiring managers can make a rational decision about what number of stamps over what period of time is sufficient to evaluate a person, trading against the risk of misreading a profile by accepting someone with fewer stamps.