In general, immigrants are less of a threat than a citizen, by the way.
This isn't even actual scrutiny either. These are stupid questions. If someone answers yes to being a terrorist, for example, congrats. You've barred someone stupid from entering the country. This is the same tactic used by "nigerian" scammers.
I'll add that some of these are completely outside of a person's control: Things your parents did. I can only imagine having a parent involved in human smuggling and then being barred from travel because of it.
Weeeeeell. No, not entirely. If you think "terrorist" you probably think ISIS and Al-Queda. But someone could have been a member of the IRA 30 years ago, and should still technically answer "yes" to this question. In theory, that shouldn't bar them from entry(given that everything else is ok). But lying on this form and saying they have never been a member of a terrorist organisation would ban them for life from visiting US if they were ever found out. So this question is not as stupid as it seems.