If you are Cormac McCarthy or Stephen King, you probably don't have to worry too much about what other people might have as far as input on your writing. For everyone else, I recommend accepting that as writers, we just can't do it all ourselves.
Get some outside readers.
Writing groups are a good source, though I have had my own particular issues with conflicting points of view. I won't get into that here.
I find that friends actually work out the best, but not my writer friends. My writer friends, as much as I respect their talent, aren't particularly good audiences unless I am looking for some mechanical fine tuning.
The reason for this being that most people that read my books probably aren't writers and have no interesting in being writers. Some will be, to one degree or another, but the majority of my readers are just looking for a way to pass the time on a flight or want something to read on the toilet.
I know this and appreciate it.
Because of this, I have learned that the best people to read my first, second and third drafts are people that never write. I tend to look for one reader that is a fan of the genre, one reader that will be brutally honest about how stupid my writing may sound, one reader that will look for the mechanical stuff like spelling and syntax and one that notices the details (like women's clothes and repeating themes).
I just can't think of all these details on my own, at least not yet. Once I have written my book and read it enough times, I know what I mean to say and my mind will make me see that on the page. I need blank slates that have nothing invested.
I recommend having multiple readers go through your drafts even before finding an editor (which I'll get to in a future post). Figure out all the angles before you subject yourself to the scrutiny of Amazon or whatever blogs are out there.
With few exceptions, there will always be someone that just doesn't like your book for whatever reason. Do what you can to whittle those numbers down in advance by taking a step back and asking for help.
Your book will thank you for it.