At first glance, it seems as though the other characters – those not in the Glass family – play the role of antagonists. In "Roof Beam," you've got the Matron of Honor. This character is not likable and makes the situation difficult and uncomfortable for Buddy. In "Seymour," anyone Buddy mentions (outside of his own family members) is depicted as severely lacking (students, critics, readers, you name it). In fact, this is what many of Salinger's critics dislike so much – this alienating attitude.
But, when you reach the end of "Seymour," you're rewarded with a rather uplifting revelation on the part of Buddy: he loves everyone. Not just the Glass family, but everyone – the annoying students and English critics included. So the antagonists aren't real antagonists, not when you learn the lessons Buddy has to offer.