The jokes might be uncalled for, but you just told us they were under-staffed and had hundreds of extra people to process. I can see why they'd be upset. Especially when absolutely zero of the hundreds of people they talk to in a day are happy to see them.
I get the impression you've never worked in the service industry or in retail. The immense fuckup that is United States immigration is not the fault of its lowest level employees.
I'm not sure how you can use "you've never worked in the service industry" as some kind of trump card, as this kind of behavior could easily get you fired from any half-decent service industry position.
And no, "voting" is not the way these things get fixed. if it was, the DMV would have stopped being miserable ages ago:
1. As mentioned above, the people most affected can't vote.
2. Even if they could, it's not clear at all how to use your vote to affect change. Which candidate exactly represents better service at government agencies?
3. Even if you knew, you get effectively four federal representative choices that could affect this (president, 2 senators, and 1 house representative). In those 4 choices you must weigh all your grievances. How high on the list is immigration staffing going to be?
The reality is that our system is not set up to deal with this kind of particular issue well. There's no good gradual feedback loop. Things have to get really bad, beyond where it's clear exactly what caused the problems, to the point where huge sweeping changes get made, probably over zealous and too far in the opposite direction then.
Unfortunately I don't think most American citizens really get to see the true face of their immigration officials. I've actually had them talk to me in a way that in any other "service" industry I would have made a complaint (but you cannot due to the power inequality, and the risk that they would add a "note" to your file).
So I eat it. But they're really rude, and it has nothing to do with their job. Most other countries manage to get just as much information about you and make exactly the same decisions without acting that way.
But police/immigration/etc in the US is kind of militaristic and authoritarian even at the best of times...
If you worked for me with that attitide I would make a point of ruining your day every day until you quit.