In the route awarding DL received ATL-EZE, then the following year CAL was awarded EWR-EZE. However CAL saw that Argentina's economy was down the tubes so asked for a deferal, when forced to chose between launching it immediately or loosing it CAL decided not to launch it.
DAL was then awarded the frequency for JFK-EZE, however they too wanted a deferal. Next was UA's application for EZE-LAX, UA when awarded decided they wanted to fly the route from IAD instead of LAX. When forced to chose between LAX or no flight at all UAL chose no flight.
The transportation Dept thus decided to postpone the new route awarding indefinetly.
All this came about as the US and Argentina were preparing for an openskies agreement, that's now impossible because of the political instability in Buenos Aires. So DL was the only carrier to receive a new EZE frequency, the ATL flight was not taken away but was to be the first of many new route awards.
However after a year of flying ATL-EZE, and the other airlines watching DL's performance the realization was that this route was not going to make anyone any money for the forseeable future.
Eastern Air lines flt # 701, EWR-MCO Boeing 757