We all have our niche. I have a novelist friend, very talented I might add, who has a wonderful imagination and has no problem at all adopting an idea for a book and weaving wonderful stories. However, the thought of composing query letters, to him, is daunting and he struggles in describing and giving a synopsis of his own work.
As I mentioned in the blog post "There's More to Proofreading Than Reading," to be a good editor one must possess good writing abilities as well. Writing in certain "arenas" comes naturally to me. In just the same way, misspellings, punctuation errors, grammar and all that is involved in being a proofreader and copyeditor just seem to stand out as if written in red ink or typed in red letters.
Everyone in the "world of words" knows what their particular niche is, and imploring the help and assistance of someone whose skills lie elsewhere ties everything together. We all work with the help of others in all areas of our lives. There is no difference in the world of writing and editing. We all do what we excel at, and rely on others whose niche is different from our own.