A lot of it seems to vary by airport, not just airline or class of service. There are some airports where every employee seem competent, nice, helpful and others where nobody seems to care at all. My impression is that different airports have cultures which encourage or discourage professional behavior. It could also have something to do with the pool of people in the area available for hire and the economic conditions of that area, in general.

Training seems to be a huge issue, as well. When employees are not trained, you can expect inconsistencies, mistakes that cause you unpleasant experiences, contradictory information, and general incompetence, even from people who would like to be doing a good job. I suspect that airlines/airports are not only not paying as well as they once used to, but that they are also severely cutting back on training budgets. When I know more about the policies and processes than they do, it is clear they've not been trained adequately. There are countless times when I've been able to avoid bad situations simply by knowing that what they are telling me is incorrect and insisting on something different.

On top of everything else, there also are simply not enough crews available, flights scheduled, and gate agents working to accommodate natural disruptions that are bound to occur.

The system is stretched so thin that any incompetence aggravates the situation in extreme and noticeable ways.