I review books in exchange for free books. I'll bet some of the authors of the books I have reviewed have felt like I missed the point of their books altogether.
Does it really matter what the author intended? Yes, it's interesting to know the author's purpose but isn't it more important how the reader relates to it?
That's why I love comments on my writing. It's fascinating to me to read your interpretation of what I have written, how it may have touched you.