Their relationship was probably the most frustrating to watch because both were good people that couldn’t get past their differences.
On one hand Donna was content with Ray never being anything other than “the cowboy she fell in love with.” Anything he tried to do that didn’t involve a horse she would give him the old “Ray, what do you know about this or that?” Or “Ray, you’re going to get hurt.” Even Clayton chastised Ray when he was knee deep involved with JR when Cliff and Jamie was going after Ewing Oil. They did treat Ray as if he was some kid.
Ray on the other hand was undoubtedly the most insecure person on the show. Anything Donna accomplished made him got jealous. He was perfectly content with Donna staying home and having a hot meal waiting for him when he got home. He had to know that that wasn’t Donna.
Their breakup was definitely both their faults because Donna didn’t want Ray to change in the least and Ray wanted Donna to change to suit his insecurities.
They both had their fair share of blame for it not working out. Ray got tired of her constant need to conquer the world. He was looking for a more traditional type of marriage like Jock and Ellie had. Ray needed a wife who also wanted that. Donna belonged with a man who would enjoy having a wife with her mindset.
I think Donna was very good to Ray when he was in trouble, such as when he was facing a murder charge. When Ray was down and out and self-destructing, she was there for him. Ray cheated on Donna with Bonny. Donna was faithful to Ray and she forgave him then, which is to her credit. Maybe she understood how someone could cheat, considering she was cheating on her husband when she started her relationship with Ray, not telling him she was a married woman.
It was hardly fair that Donna, while insisting how important it was for people to broaden their horizons was so opposed to anything Ray ever did to become a more well rounded individual. She actually said to him: "People grow or they die." Well, I guess that means Ray was gonna die! According to her outlook he was, since she tried to shut him down almost any time he tried to develop, to expand his interests. It was a classic case of: "Do as I say, not as I do."
It's worth noting that near the beginning of their relationship, before they ever got married, Ray said he didn't think things could work out for them because they had so little in common and had such different interests. Donna was adamant about marrying Ray; she even went to Jock to ask him to help convince Ray to be with her! That's a bit much, don't you think?
Donna told Jock she was in love with Ray and he said he believed her, but added: "A good marriage is based on a much more stable foundation." Ray and Donna just didn't have that stable foundation.
Considering that, it's hardly one or the other's fault the marriage didn't work. If I've got to say which one was more to blame, I'd have to say Donna has some more of the blame since she's the one who ultimately stopped wanting to try to make their marriage better.
It was pretty cold to leave Ray as soon as she got pregnant and move half way across the country so he wouldn't even get to be around his kid. I can't believe that a woman in her financial positon couldn't even be bothered to take a year or two off from working for the good of her child. In those very early years it's critical for a baby to bond with the mother, who typically tries to spend as much time as she can with her baby. Not every mom can afford to take a year two off, but Donna certainly could! It's not as if she had a job she'd lose if she took that time off. In fact she was specifically moving to Washington DC to start a new career. Donna was going to become a mother, for the first time, and she couldn't justify waiting a year or two before starting the next phase of her career so she could spend that time with her baby?