I guess I am made of weaker stuff because I would not be able to stand that kind of rejection over and over.
Sometimes I have tried to count (in the movie) how many times directly or indirectly Ennis rejected Jack's idea to live together, or be in close proximity, and I can barely finish...Jack was rejected so many times it was heartbreaking. But given the time, who Ennis was, etc., I do understand.
Evidently I really am the least romantic person on the planet. If you love someone, you do what you have to do. Jack asked for more in their relationship, but he never made it a condition, because he probably almost certainly knew Ennis couldn't do it. Ennis didn't reject Jack as much as he rejected the idea of them setting up shop together and being a couple.
Yes, Ennis rejected Jack on a number of levels throughout the film. However, they also had years of tent-shaking, teeth clanking, heart-stopping, deeply-involved sex and tenderness that Jack, no doubt, enjoyed, although it was never enough for him. Even though it appeared Jack was taking steps to move on, he never let on to Ennis and made no attempt to end the relationship, such as it was.
In our time of cell phones and email, we forget that it wasn't always this way. Everyone wasn't always at everyone else's fingertips.
I guess I'm also in the minority with having partners that might not have been willing to make sacrifices for the relationship like I was. The "Jack" in the partnership has to decide if "unsatisfactory" is better than nothing. I think for both of them, it was.