Why do people want to live in the US and jump through all these hoops and be subject to arbitrary detentions, anyway? The bureaucracy is hellish. Many other countries have decent living conditions and don't randomly mistreat the people trying to make a living, nor do they behave understanding or cruel at the whim of whoever's in office. Or if they do, it's not as bad as in the US.
Is it just that the US is closer to these people than other, saner countries? I can understand if that's the actual reason.
Also: why do border officers have so much power? It seems wrong. They are low level employees, they shouldn't be able to change your life (or trip plans) just because they feel bored and want to spice things up.