Help me out here will ya?

Since all of us can sometimes be called a "bitchy little artiest fanboy/girl" How do you tell a writer that you love their story and world but they have no concept of how to write it? and with Audio/Podiobook authors that they need to either use words they know how to pronounce, or look up how to pronounce them?

I ask this because I love reading and listening to Audio/Podiobooks, especially on long trips, and I believe that some of these authors deserve more credit for their creativity. Though frankly, I don't see them ever getting the amount of credit they should, unless they fix the above mentioned issues.

So how can I tell them those types of issues without offending the author? Is it even possible? I want to and like to help people improve what they do, but this requires tact and that's something I'm currently lacking in this situation.