I completely agree and stupid reasons such as jealousy and being too overly clingy shouldn't affect the ability of a person to see what is right from wrong. If they feel like they are being threatened then they should go and leave the cause of the threat and never try to accept it. It's either treat you right or leave them alone.
I didn't get the feeling that the author was condoning the abuse or reinforcing a view that abused people deserve it. I thought the portrayal of the abused was just that-portraying the insidious thoughts of a victim of domestic abuse thinks and how obviously distorted that thinking/justification is. But naturally not every reader is going to interpret this (or any other) work the same way so I will just agree to disagree with you on that point.
The seme even blamed the uke for getting beat up.
Abuse is abuse and there's nothing one can say or do to justify it. Although the couple are cute together and I appreciate their kind of love I still can't get over the fact that the 'Uke' thinks that just because his ex bf could understand his sentiment over his unrequited love and is jealous of his childhood friend then it's alright to be abused and beaten up.