Originally Posted by EWR764

That was a decision made toward the end of the Smisek regime. In a nutshell, JFK was a high-cost operation for United and was underperforming EWR in most metrics. An opportunity arose for United to consolidate at EWR, reduce competition from Delta, and cut costs by closing JFK. United overestimated the willingness of corporate customers at the West Coast (specifically LAX) point of sale to migrate to EWR, despite the promise of a better schedule. That move cost United previously-exclusive (and lucrative) business and has taken it out of the running for other contracts. It also strengthened competitors. Virtually all of the C-suite from that period has since departed the company.

JFK is and always has been the preferred airport for travel TO NYC from the West Coast and international. For NYC-originating traffic, EWR has a much healthier share of the O&D market, and United's focus was too heavy on the New York point of sale.