My anecdotal experience is similar. Entering the US on a US passport is a breeze. Entering the EU on a US passport felt very hostile. I would imagine it's the same everywhere - it is the most fundamental job of a government to secure its own borders and maintain its own power.
I have found entering the US after visiting the EU (Schengen, technically) to be more hostile.
The EU person typically looks at me for a second or two and then stamps. Maybe they ask me how long I'm staying, I say "a week" or whatever, and they stamp.
The US people (EWR or JFK, maybe it varies) have an attitude that suggests that they think someone who visited Switzerland or Denmark is likely to be coming back from a vacation training with ISIS. They also really can't decide if my girlfriend is supposed to come to the booth with me, all of the rules suggest no since we are not a family, but then they tend to get upset after they ask me if I was traveling alone and I say no.
Interestingly enough, I travelled to the San Diego two years ago and I was expecting a round of “premium questioning” because I had a (long expired) multi-entry visa for Syria in my (now expired) passport (I was in Damascus in late 2009), but the guy didn’t care at all, just asked what the purpose of my US visit was, spent a few minutes looking at my passport and checking his computer and then he welcomed me and sent me on my way. It was all rather painless and everyone was relatively friendly.
That isn't too surprising, is it? That would be true for almost every democratic country.
As an EU citizen, I found entering China less scary than the USA. The Chinese officers were almost painfully polite and matter of fact, whereas the TSA officers were borderline rude and threatening. I'd really lover to go for holidays in the USA again, but not anytime soon. Since I don't have a FB, Twitter or IG acc't, I'd probably be denied anyways.
