I don't think I could disagree more...
On one hand, I'd be willing to bet that the percentage of the audience in an adaptation (at least one that's intended for a mainstream audience) who know/care about the source material beyond vague generalities is much much smaller than people assume.
On the other, it's not hubris or "thinking you know better" to acknowledge and try to deal with the realities of taking something that was written for one medium and translating it into another. Especially in this case when there was barely anything written...at all. Case in point for the billionth time: Tolkien purists (up to and including the man's son) are notorious for shitting on Jackson's first trilogy, and yet they're viewed in much the same way that you described the books they were adapted from. "The foundation of modern fantasy" filmmaking.