Why you would want a relationship like theirs? They were different personalities, even as children; but they complimented each other the way peanut butter goes so well with jelly. Ellie was outgoing where Carl was shy. She didn't try to change him and he wasn't put off by her. Quite the opposite happened, they fell in love. They supported and believed in the other's dreams--- Ellie wanted to move her clubhouse to a cliff in Paradise Falls and Carl merely wanted to go to Paradise Falls like the explorer both he and Ellie admired. Some time later after they married, they did not allow their bad news of not being able to have children to ruin their relationship. Instead, they pooled their money together to save to make their childhood dream a reality-- a trip to Paradise Falls. After many years, once they had the money for the trip, they were unable to go because Ellie became sick and eventually died. But even in his loneliness, Carl continues to love his wife because he does go to Paradise Falls for both of them-- and his method of traveling to Paradise Falls causes Ellie's dream of a house on Falls to come true as well. Who doesn't want this kind of support, care, commitment, and genuine love in their lives?
Why you would not want their relationship in real life? Well, if you must have children as a result of your relationship, then this would not be the kind of relationship you would want. Also, if being super rich is important to you, then theirs would not be the life for you. Lastly, if you cannot see yourself actually keeping the vows "Till death do us part", then this is not the relationship for you. However, outside of children and superficial things, this is truly a model relationship.
So is this a relationship to model yours after?Absolutely. Their relationship is one of acceptance, one of fun, and one of real love. They make marriage not seem like a job. Their marriage was a friendship, a family, and abundance of love with just the two of them. It is truly the most moving couple in a movie even though the entire span of their relationship happens within the first 30 minutes of the movie. Watch Up, and you'll see.