My biggest complaint against shipping is that it is invariably contrived, and oftentimes reaches the depths of incest as well. Consider that shows typically begin with a set cast that forms the core "family" of the show. Later, if the show lasts long enough (it doesn't take very long nowadays, two seasons, give or take one, seems to be the norm), the producers feel pathologically compelled to pair off the available characters. From this compulsion results forced and unnatural characterization that strays from whatever organic development it could have otherwise followed. Example: I've read speculation that Donna from The Horrible Nu-West Wing is going to be promoted so that she and Josh can have a torrid affair and destroy their careers. To break kayfabe, or to view the situation from a critical standpoint, is the pure manipulation of character for the sake of strained melodrama.
But I didn't back up any of my claims with concrete example, I give myself a C+.