this post is living in an idealistic world.
lets be real. this isn't going to stop anytime soon(her having to devote herself 100% to her mother).
they're not married. If they're not going to put her anywhere she's going to need support and care for a long time. could be upwards of years. why is poboy going to make his own life miserable for this woman just to be "supportive?". If this was "the girl" then maybe but it dosn't sound like he has any intention of marrying this one. And even then, it'd be a VERY hard decision. I don't think you truly understand the ramifications of a situation like this.
and yes, sometimes it IS about you. You make decisions in life and they affect the people around you. Her decision is to take her of mother when she's clearly beyond the ability to take care of herself. She's sacrificing her own life and in turn, the life of thsoe around her. There is nothing wrong with not wanting to be a part of that. She has other options,she's just not choosing to exercise them.
Until you've actually seen this taken place you can't really speak of it, no offense. I've seen it first hand within my family and while it seems noble, in the end it doesn't do anyone well. I don't see how you can so adamantly berate someone over something you can't truly understand.
I've been there CW/ My grandmother had a heart attack recently and has been in bed not being able to take care of herself. We would NEVER put her in a home! We are human beings, we make sacrifices for our loved ones. You didn't grow up all by your handsome self now, did you?!

My best friends son has a disability, he has a dysfunctional kidney-he was born that way. The doctors told her that she should just give him up and that he would never be able to speak or walk. She didn't give up her son. She said the thought never even crossed her mind. As a matter affect her son is gonna be 15 in June and he could talk and play just like a normal kid. Yeah it's tough on her, but her BF never walked out on her. He actually tested to see if he could be a donor.
My point is, you don't walk out on someone when shit hits the fan. In this case, she is frustrated and probably very tired. This is when he is suppose to be there for her, and be supportive.