I woudn't say that they have nothing. Susannah, especially, has quite a lot of worthwhile things in her life in NY -- she has her friends, Papa Mose who is like a second father to her, money and a cause to fight for. Of course, she also has schizophrenia in NY.

Eddie actually has the least amount of close, personal ties to NY after Henry dies, which is ironic b/c he's the most homesick one of them all. I just find it somewhat convenient that Jake's parents are so bad that they're so easily dismissed from the equation. Of course, I also found it a little too convenient how quickly Eddie and Odetta fell in love, but that's another thread.