This is what drives me mad. This is such a violation of every principle of good hospitality. By delegating responsibility for one's safety away from oneself to the responsibility of the purveyors (or overseers) of the mode of transportation, we all end up being treated as threats until proven otherwise.
It is such a tenuous balance. Excessive restriction of the conditions under which hospitality is granted leads to a breakdown of social reciprocity, intensification of in-group mentality, and alienation of the outsider. This stratifies and jeopardizes the ability of these myriad in-groups to coexist and transact peaceably, detracting from the possibility of maintaining any semblance of a national/international unity, or at least peaceful polity.
It's diplomacy, in essence, at smaller and more localized scales. Most societies have carveouts for providing for the need of the outsider, because tit-for-tat is such an easy state of affairs to end up in. Mind, the tit-for-tat part is implicit, not explicit, as most text on hospitality emphasizes the duty of the host to care without concern for [individual] reciprocity. Collectively speaking however, the way one culture recieves another does have an impact on overall relations between polities.
I just wish there was greater emphasis placed on this. I get it, lofty ideals tend to be the first to get binned, but sometimes the ideal is worth tolerating a greater degree of perceived immediate risk in order to facilitate a much larger payoff in terms of unity of action across non-emphasized in-groups.
Sometimes it's the difference between all travelers looking at and being suspicious of each other in transit, perpetuating macro-level conflict into every strata of everyday life, and a group of strangers coming together, and momentarily sharing the unique opportunity of traveling together, and being able to freely exchange in an environment of goodwill and camaraderie, and to be assured of unity of action through dissolution of fear at having to react to defuse violence on behalf of the traveling group.
Dissolution of macro-scale tension must begin at the bottom Of the social pyramid. Trying to work from the top down is a fool's errand.