Ie, cardholding need be blind to recruiters. Ie, insteadof <Do you have work authorization?> as the first question [no less], it need be enforceably ILLEGAL to try fish info on it.
In practice that can't be fully done without also blinding a lot of other things. but having Single Market enforced by law certainly will reduce the paygap found today in equal lvl-to-lvl comparisons (top x% vs top x%; differing only in cardholding).
re "vent" "disrespectful"; I contend that those folks actually trying to be assholes are Americans. It's likely the comparison you saw was just done in a neutral and nonhurtful manner/intention, albeit not of PC enculture.
It is possible to be impolite, ungrateful, obnoxious and correct.
This a big news to me.