This is all getting a bit off-thread, but:
1) I am sure there are sensible ways in which genuine troublemakers (be they drunkards or habitual late-arrivers) can be stopped from booking flights. Here in the UK, for instance, we have a blacklist of soccer fans who are not allowed to enter stadiums here. The same must be possible for aircraft.
2) I am equally sure that nervous passengers ought not be banned, partly as a matter of justice and partly out of concern for the negative
PR that would attach to such an action.