I think it's more a dig at American airports. A couple of differences:

1) Anyone transiting the US must go through immigration, even to get on another international flight. That's not the case at places like ICN (or most anywhere). Big advantage, and it allows you to spend more time airside in shops, which often are much better/nicer than US airport shops (although typically stuff you can buy in the US for less).

2) JFK is awful as an airport, even among American airports.