> Therefore, I wonder the real reason but can't think of any.

You shouldn't think of governments as agents with a singular, unified purpose. What you're observing is the effect of many agents with misaligned incentives, and a huge coordination problem. All this leads to a situation where large costs are incurred for no real purpose, because no agent is incentivised to put what you called 'marketing' in doubt.

For example, it's a huge cost for a politician to argue that fear of terrorism is overblown. So pretty much none of them do that. TSA have no incentive to reduce their powers. Etc.

> "not allowing terrorists/drug dealers/illegal workers etc. etc. inside"

All three of those have an access to a very sophisticated immigration scam operatives. Terrorist get extensive training in faking their identities, drug dealers have huge network of contacts and insider moles and illegal workers know the trafficking cartels.

The real reason of American immigration fiasco is deep rooted racism and against primarily non-white people. You will barely hear anything from any politicians about white people who illegally come and stay in USA from Canada and Europe. If H1B beneficiaries were mostly British or Canadians US government would have increased the limit 5x by now.

> All three of those have an access to a very sophisticated immigration scam operatives.

While that is true in many cases, in many others it is not. I lived on a border town for a few years and made friends with some DHS agents there. Listening to their stories re drug trade I got the impression that many of the people carrying drugs over are actually poor, uneducated, uninformed, etc. While some of the techniques may be sophisticated, I got the impression that the traffickers themselves frequently were not. I would imagine basic abrasive interrogation techniques would be reasonably effective.

Devil's advocate -- maybe the poorly educated, poorly trained traffickers were overrepresented in the sample of traffickers border agents encountered, because, by definition, a successful trafficker is not caught or observed trafficking.

I flew to eastern Europe three years ago and had a stop-over in Tegel both ways. It was like traveling in the US before 9/11. I felt like a human being whose rights were self-evident. It was civil. I felt human. I also felt ashamed of the industry my country has built out of fear.

Try flying to Europe from an eastern bloc country, see if you feel civil then.

In America we take our prosperity for granted. We assume we will always be rich and don't need to compete for tourism, open business and trade, general reputation etc, especially with "foreigners."

Same here, I love Germany! <3

Germany loves you, too