Kirby makes strange statements. It was "wrong" to leave, but it's also "wrong" to return. Okaaaay. That means JFK was a marginal operation at best, and one then can't easily say it was "wrong". Also UA doesn't have the aircraft to operate PS at both JFK and EWR at a reasonable frequency. Have to take this with a grain of salt since his former airline doubled down on premium service from JFK and is a fraction of the size of UA's PS at EWR.