Again, you are not basing this on any facts. Use facts, don't just assume.
AA's profit margins to Europe are 17.7%. Delta's is a slim 3.2%. Delta essentially supports the smaller markets - many of which are not profitable - with the bigger markets. Don't just assume that because Delta flies to Budapest and Pisa the routes print money. Some niche markets work, some don't. AA perfers to avoid niche markets, but that's going to change. Unlike Delta, however, they are going to be conservative about entering all these niche markets so that it doesn't take a huge toll on their trans-Atlantic profits, as it has on Delta, who has the worst profit margins of any U.S. airline to Europe by a significant amount.