Imagine that you have a novel coming out. Imagine Publishers Weekly giving you a review. Imagine it reads something like this (author, title and character names redacted):
"[Author]'s debut introduces a likable if predictable hero, [Senior Detective], a white knight in the dark city of New York. Though pondering retirement after 27 years on the force, [Senior Detective] is content to nurture a new partner, [Junior Detective], a young NYPD detective who's quickly risen in the ranks through equal parts skill and political opportunity. . . The author excels at moving his plot forward and creating a realistic landscape that shows both the politics and practice of police work. A wonderful husband and dad, [Senior Detective] drops chestnuts of wisdom at every turn. [Junior Detective] . . . comes across as fawning and naive. Through several subplots [Author] lays the foundation for future entries, but their success may require a new dynamic for the syrupy monotony of the two main characters' relationship."
Hmm, imagine your review likening your work to a root canal.
The kicker? After less than a stellar review for a debut novel, this is a 100,000 first printing.
There is no way to underestimate the desire of some agents/publishers to present dull characters that have no originality.