Superman Earth One tells the story of Clark Kent come way of a Twilight novel. He's a young hard body who is terribly unhappy. You see, Clark has all these powers, but he can't figure out what he wants to do with them. In an interesting twist to the Superman mythos and one of the best scenes of the book, he tries his hand at numerous professions, ranging from professorial athlete to research scientist. Clark just wants to fit in, something he has never been able to do because of his powers. (Query if this is a tacit removal of Clark's time at Smallville High School from the new "modern" Superman origin.) But, he's under massive pressure from his parents to use his powers to become a superhero.
The pressure being exerted by the elder Kent's creates the false emotional conflict that permeates through the rest of the book. Why on earth do they want their child to be a superhero? (Going as far as making him a costume and giving him stern lectures on why he should never wear a mask.) The Kent's insistence that this is the most noble and best way for Clark to use his powers comes off as strange, and really makes little sense in a world where cape wearing vigilantes do not exist. Surely there are numerous ways Clark could use his powers for the betterment of mankind that don't involve him wearing spandex and punching bad guys. At one point in the book he shows a great knack for science by solving an equation that allowed researchers to create cold fusion. Wouldn't using his powers in this way help more people and be far more noble? The foundation of the central emotional conflict of the book, whether Clark is going to "take the hard route" and become a superhero or "take the easy way out" and use his powers in other ways, is just nonsensical. It's based on the false premise that somehow superheroics are better/more noble/more helpful to the world then any number of other imaginable uses of Clark's powers.
As emotionally conflicted characters are wont to do in modern teenage dramas, the reader knows about this conflict because Clark whines about it. It's not hard to imagine that by the book's end, the constant whining about how hard it is to have super powers has made Clark thoroughly unlikeable.
So we have an unlikeable protagonist suffering a false emotional conflict, what could the writer do to make things worse? Have the conflict solved almost entirely through forces beyond the heroes control. Clark ultimately makes the decision to don the cape when an alien armada threatens to literally blow up the planet Earth. Clark of course decides to fight off the alien menace, and subsequently decides to become a superhero. But is this a satisfying resolution to the book's emotional conflict? No, not at all. It only serves to make Clark a more unlikeable character. What else was he going to do when placed in the situation where only he could stop the planet from blowing up? There's no real choice. Death or superheroics? I guess I'll take a set of spandex please.
By removing choice from the resolution of Clark's emotional conflict, the book strips away the facet that makes Superman an interesting and enduring figure in American fiction. Superman works as an enduring character in American fiction because he represents the mythology that people are inherently good. When given the powers of a god, Superman uses them only to better the world around him. He makes the choice to do so, even though it would be easier and more personally satisfying to use his powers in other ways. It's the choice between altruism and selfishness, not the choice of using his powers to be a superhero or using his powers to follow some other career path, that make him an interesting and meaningful character.
Superman Earth One essentially misses the point of what makes Superman so super by forcing Clark to become a superhero. If he hasn't made the choice to use his powers to help the world around him, then he really hasn't developed as a character past the unlikeable whiny emo kid from the beginning of the book. At the end of the book he's just an unlikeable whiny emo kid in a cape, not a young man coming into his own and making hard decisions about his path in life.
The false emotional conflict and its poorly handled resolution are the actual problems with Superman Earth One. That is not to say that the other numerous criticisms that have been leveled against the book are wrong. The pacing is off and Shane Davis' art has never looked worse, but these problems pale in comparison to the major substantive storytelling problems.