As I read their post, they were actually saying something more akin to "it's perfectly fair for low and middle income people in rich countries to complain about policy regimes limiting their ability to share in domestic productivity gains even though there are much poorer people overseas, since those policy regimes aren't actually anything to do with those poorer people"[1]

Which didn't strike me as the sort of sentiment you'd tend to disagree with either.

[1]by implication they're arguing they'd be less bothered if their purchasing power wasn't growing due to outsourcing competing with their job, since at least that'd be helping poorer people out.