"What we believe about this classic literary work is simply false, yet society has accepted it as true. It's as if the novel has been cast aside and forgotten, and that probably matters most of all. [...] Frankenstein has been so overshadowed by film versions that the book is no longer relevant to most people."
Watkins specifically criticizes all the extant Frankenstein films for altering details small and large, and for emphasizing some aspects of the plot over others, neglecting the themes that he considers most important to the Frankenstein story: the overreaching of the scientist and the suffering of the creature.
Watkins and I disagree that these themes are unaddressed in cinematic versions; but even if they were not, Wakins appears to be decidedly more rigid on the ideal relationship of printed page to celluloid frame than I. He believes that any alterations to a novel in adapting it for stage or screen is a "corruption," and he marvels that book and film are "two types of media telling completely different stories." Well, yes. Movies and books are inherently different, not just in how they tell their stories but in the types of stories they can tell. The cinematic Dracula differs greatly from Stoker's novel, as does every adaptation.
But the larger point is this: Is Frankenstein to be understood primarily as the novel Mary Shelley wrote, the movie James Whale filmed, or something else? Watkins wants Shelley's novel to be seen as the authentic Frankenstein, and all others as "corruptions." Instead, I choose to see Frankenstein as a modern myth, and like any myth, it accrues variants over time as the story is told and retold, continuously adapted to changing circumstances and needs. Mary Shelley will forever be the creator of Frankenstein, but she birthed something larger than a novel, a myth that has escaped the page and even the screen, to become simultaneously novel and movie, stage play and Aurora model kit, and so much more.
To complain that filmed versions fail to reproduce the novel line-for-line is to miss the point entirely.