Ah yeah, I could imagine that. Foreign passport + visa puts you in the "foreigner" line, even if it's a long-term visa, which is usually slower and typically has more suspicious / less helpful staff. Green card holders get to go through the "U.S. Citizens & Permanent Residents" line, which is a bit friendlier and faster.
(Not that I disagree that the whole setup is ridiculous and probably doesn't meaningfully add to security.)
Especially one return from a conference where the minimum-wage-moron on passport control didn't understand the concept of visas (to be fair he had a limited understanding of the concept of passports or even other countries) and allowed me in for 24 hours which I spent queuing at LA's delightful immigration office downtown.
Still, well done to him for protecting the USA from another foreign Caltech physics prof.