I honestly think one of its central problems is actually its protagonist, Moses. He's pretty much perfect, leaving him very little room to grow. Queen Nefertiri is a monumentally more active and interesting character (though she has her inconsistencies) and ultimately Moses' attitude towards her (about saving her child, in spite of her saving his) reads like he's drifted away from his basic humanity.
DeMille's defining characteristic, for better or worse, is that there's no difference between intimate character scenes and thousand-extra vistas. All are equally bombastic, sweeping in emotion and gravitas. So his characters may be broad caricatures, but they have a grand, emotional punch. His vistas may be gaudy, but there's a surprising intimacy allowed. Narrative fidelity be damned.
It would be easy to dismiss Cecil B. Demille's 1956 retelling of the Book of Exodus as pure Hollywood melodrama, but that would ignore just how good it really is. Demille frames the film as if he's still working in silents, and the dialogue tends toward the overwrought. But it's a traditional Hollywood epic in the best sense of the word, overcoming its hokier elements with sheer conviction and grandiosity.