It think the risk is in transparency. If I piss off an airline employee in some way and they decide to punish me in this way with no recourse it's a problem.
The whole thing exists outside the regular justice system. Even if the airline employee puts you in the list in good faith, the criteria they used to put you there would be somewhat arbitrary (define "unruly") and not weighed against any kind of precedent for similar infractions. Appeal is also difficult.