They reason why no one attended Gatsby because they were just fans and they only liked his huge ,fun parties. Nick was there because it had a close friendship with Gatsby in fact he knew the hole truth about Gatsby.Jordan didn't come because I think she moved some where far.Because she was mad at nick .Tom was the reason why daisy didn't go in fact daisy did not even know that Gatsby had died until a few years later.Nick had called to tell about Gatsby death and they hung up the phine and ignored his call.
