In one word - "Freshness"
Beer has a shelf-life, and some beers age less well than others. Presidente, it seems, does not store well. Perhaps it is not laden with preservatives and stabilizers like Budweiser!
Also, think about the temperature variations as it is bottled in Santo Domingo, placed into a swealtering cargo ship hold, unloaded in some cold climate, placed in a warehouse, distributed in a truck, stored in the back of the bodega, placed in the refrigerator case, etc. Temperature consistency is important in maintaining original flavor.
All stories about the beer being "different", bottled in Virginia, brewed in Pittsburgh, etc, etc, are myths.
I also agree that the environment in which you drink it matters. Nothing tastes very good when consumed under the Cross Bronx Expressway.