He apparently had his paperwork in order and was rejected when he tried to travel.

Spin it however you like, but the fact is that he was denied entry into the US?

Whether or not he can pay (time, money) to go in the future is irrelevant to being denied today?

Regarding the entire esta vs visas... I'm lucky enough to have passed painlessly through VISA and I don't understand the difference between them? You have to apply for both? You have to provide your identity documents, information about yourself, payment? The only difference I can see is that you don't need to visit an embassy? Why do we draw a distinction, other than marketing?

My purpose was not to criticise your comment, but to offer a starting point for reflection. It is not a secret that (in recent years) the number of people subject to more stringent authorisation procedures are constantly increasing, and this without counting the no-fly.

Having been a great admirer of the US, I can say that what I admire are some principles, principles that seem forgotten. They are probably forgotten because when you teach a CBP employee to look for only the worst of people, this will eventually find something suspicious in anyone.

The recent run into exploiting software vulnerabilities could explain why there’s a focus on developers/hackers. But just putting a critique is not constructive, remembering where we come from, what are our principles, why we have them, and their purpose, is much better to motivate why it's wrong to "discriminate" someone.

It's not just slow and annoying, it's wrong because he’s not responsible.

The nuance you're trying to invent is meaningless if you miss your flight and the conference.