Yes it was so rude to call out an “only Punjabi” problem, when really 'you cannot marry outside of family/tribe" issues is equally prevalent in Pakhtoon, Balochi, Sindhi cultures. Just like Punjabis, other communities when get together talk liberally about their little regional customs and phenomena. Yoy say its Punjab’s obsession, I’m a Punjabi and I’d never ever bother talking about Punjabi tribe system with my Balochi friend, similarly they won’t get into nitty gritties of their regional customs because everything is so different and irrelevant to other party; now should a naive outsider think that Pakistan have no concept of tribe/caste just because he’s never seen two Pakistanis ever discussing it? So I see nothing but bitter, self defeating generalization.