Why Does Nick Feel Responsible For Getting People To The Funeral Of Gatsby?

Nick Carraway was basically Gatsby's only friend who really cared for him. Nick assumes responsibility for Gatsby’s funeral arrangements because it is the decent thing to do and he knows that no one else will do it.
Nick states that he feels as though he must "get somebody" for Gatsby's funeral. He says, “It grew upon me that I was responsible, because no one else was interested — interested, I mean, with that intense personal interest to which every one has some vague right at the end”.
After Gatsby dies Nick, feels that many people will attend his funeral, but after many calls, he learns otherwise. Nick is shocked to find that Gatsby’s closest friend will not even attend his funeral.
At Gatsby’s funeral, Nick finally comes to turns that Gatsby had no true friends. All of Gatsby’s friends just used him for his money. This makes Nick upset because he always tried to support Gatsby. However, in the end, Nick has to face that Gatsby died alone.