Ok I gave up on reading this whole thread pretty quickly, but have discussed this a lot. I definitely think your opinion changes when you see the show, depending on whether or not the actors do justice to their roles. I saw Josh Davis and Betsy Morgan at the Everyman Theatre and they were both fantastic, so it's not like I really sympathize with one because the other was acted badly.
Before I saw it I assumed Jamie was to blame because he cheated on her. I think his part in this is more obvious, but Cathy did plenty to ruin the relationship, too. It was probably already mentioned but in the first song she says "Jamie is probably feeling just fine, but I'm still hurting" and "covered in scars I did nothing to earn." This is where I think we can see what she did wrong, because at least Jamie recognizes and apologizes for his mistakes. Cathy sees herself only as a victim and refuses to accept that maybe she pushed him away. I still feel Jamie is more to blame, but it's easier to see what he did wrong because it's nearer to the end of the show and more blatant. Cathy bothers me for many reasons, but those 2 quotes were really what made me sympathize a little with Jamie.
What happened to Andrae?
Fan: Oh my god! You're, like, standing right there and, like, looking right at me and, like, oh my god!
Anthony Rapp: Yes, that's a pretty accurate discription of reality.