Well, first of all, why do you feel their relationship is "shitty?" It's a pairing that has been explored a few times before and in those books I didn't find them "shitty", personally. The idea that two of the strongest people in their world, finding a kinship is hardly "shitty". And what would you prefer exactly? Something completely out of left field?
To me, the pairing is very safe in that the pairing between the world's strongest man and the world's strongest woman - neither of which are born of Earth and have been looking for their humanity.
Because both are constantly trying to be "human", it's their exploration into what it means to be human is far more compelling than "hey, since we're so much alike, let's make out", which seems to be what DC is currently pushing. :/
Though traditional, Lois compliments Clark's struggle between his identity as Superman and his life as Clark Kent. She herself is very human in desiring Superman but overlooking the simple Clark which makes him question how he can exist as both. I liked that together, they both discovered what makes Clark really Clark and that Superman is also Clark.
Diana, on the other hand, was raised by a Matriarchal society. So of course, she wants to find out if the world is all that it's cracked up to be. If anything, Bruce is everything that she's been taught to avoid and yet, he's also everything that her people valued in their heroes. So I liked how they would needle at each other but it's always a learning experience. Also, he usually went with the direct approach to make her see things while avoiding treating her like glass. Steve, though not as brash as Bruce (or really as callow at times), was also good for her too in that he respected her as a whole.
Clark and Diana always have more of the sibling-vibe because they really relate to one another's struggles to be "human". So that's why I never saw anything romantic between them in all of their history. Despite the initial romance, they both realized that they were closer to being siblings than romantic partners.