incidents and accidents, hints and allegations

I think it's that Joe never forgives himself and never accepts himself. This is a play in which people get about what they expect. Not what they deserve; what they expect. Except Prior, who is blessed, with more life. Louis expects, from the beginning, that he is going to be unable to cope, that he will leave Prior, that it will be unforgivable between them but that because he is basically a resilient asshole he will eventually forgive himself-- and that's what he gets. Roy Cohn expects that he'll be able to angle something because he's just such a charming bastard, that everyone's going to forgive him even in the afterlife because he knows how to work the system, and that's what he gets.

And Joe expects that everyone is going to hate him and Harper isn't going to take him back, and, in fact, that's what he gets. He is a gay man and a Mormon, and he neither comes down on one side or the other of that contradiction nor embraces it as a contradiction that he can live in.

In addition, I think Harper taking him back would have been utterly horrible for both of them, I think that marriage was a trap for him as well as for her. We don't see him in the some-years-later bit, but I think he has more of a shot at being happy than he would if he were in that marriage. I think the thing that the play smacks him around for is not the leaving but the trying to return as though none of it had ever happened.