Before I became a Swedish citizen I never had a bad experience traveling back into Schengen, border agents were always cordial even on the instances where they were stern and serious. Even had nice interactions sometimes, at Schiphol with Dutch agents once they were quite funny, and light-hearted.
Every single time I traveled into the USA I experienced CBP agents being rude and suspicious, treating people like cattle on immigration lines, being talked down when being questioned, etc. The experience applying for my B1/B2 was also really annoying, not a great one being interviewed and grilled by a consul.
It's definitely different to go through USA's borders than most other places I traveled to.
In all cases it was a good experience. The process was more or less straightforward, and I was treated with respect (and in some cases kindness) by the public servants I dealt with.
Not once I was treated like I was an unwelcome guest.
Not exactly black, but far from white.
And yeah, the cliche of AMericans being haughty gung-ho cowboys is true. They bark at people and clearly play the bully.
From my experience as an American I have never had the kind of hostility, the power trip, the 'why are you worthy to be here' that I receive coming home be experienced in any other nation.