1. Most of the time they are correct but not for the reason we imagine;[1]
2. Most the time the procedures should be followed even if it seems crazy[2];
There is no pleasure in any US service to cancel or deny but they should work on procedures to be more fair. in case [2] even if I am not even close to match they HAD to check everything before releasing me. So if you have a common name disclose everything (travel to other countries, parents, friends, everything).
If you think US border is "bad" you should check European (London). They do not require visa but if the customs is in a bad day they will reject you and sent you back while you wait in detention.
At least US has the courtesy to ask for a visa before most of the times.
[1] - The form asks if you have any parents and you did not disclose (even distant family).
[2] - In my case my name is on the Wanted Database. There is a terrorist with similar name. So EVERY TIME I approach customs there is an scary look when they digit my name and I should go to "the room". After some time: "Sorry for the trouble have a good one."
Disclaimer: I do not work for US gov or have any affiliation but I think they tend to be more fair. If not please check Middle East countries or Europeans.