Of course, it's kind of the point of having borders and control, if they let anyone in without verifying, it's not even worth having a border.
Going from France to UK is like that, and before Shenzen, it was like that from EU country to EU country. When I was young, we had to wait for 2 hours with my parents while they checked everything was in order for a Spain border crossing (we were in a big RV so it makes sense).
People on HN have very soft views of the world, being too idealistic libertarian or some sort of socialist derived ideology.
Most people may not be criminal but you have to process everyone crossing the border as if because otherwise it's pointless and you will never catch the criminals...