It is not the audiences that “cannot grab a hit”, but the broadcast networks. (In that New York Times article, the sentence before your quote is “Think about the box that the broadcast networks are in.”) In the U.S. at least, “over-the-air” broadcast networks – using FCC-controlled portions of the electromagnetic spectrum – are subject to more-restrictive standards than are cable networks. (1, 2). As such, they are “in the business of not offending mass audiences”. “They cannot even grab a hit when it comes lurching through the door” means that they cannot sign up a show about zombies that, for example, shows “a pack of zombies ... lustily feasting on human innards”. Zombies often are portrayed as lurching about as they walk. To lurch is “To make such a sudden, unsteady movement”.