I ask the question because there are threads such as this one which, for example, ask what attire one should wear when in First Class on an airplane.

It seems that the more I travel, the more of a familiar license travel industry personnel seem to feel they have when addressing me, whether I am an occasional customer or the highest-tier elite member.

Should this practice be accepted regardless of etiquette, or are there limits that those in the travel industry should follow when addressing their customers?