Beta readers are important helpers for most authors. Beta readers give you honest feedback without hurting your sales ranking with bad reviews. Beta readers give you the opportunity to make your story better before you make it available to the public. And beta readers can be your greatest fans and shower you with great reviews once all is said and done.
That being said, we can think of lots of reasons why you shouldn’t always listen to your beta readers.
Some beta readers are more ‘helpful’ than others. There are some that like to point out every tiny and big mistake you make in your novel. And while it’s helpful to receive feedback, getting 100-page document with things you need to fix in your story is anything but motivating.
The thing is those beta readers aren’t necessarily English majors. They could be wrong. And do you really care whether that one sentence on page 59 needs a comma or a semicolon?
Apart from spelling or grammar (things you can look up and verify), beta readers can only give you their opinion of your novel. That’s great. After all, you asked for it. But whether they tell you that your book needs additional sex scenes or less backstory, then that’s still their opinion.
You should definitely take what they say into consideration. Maybe you did go overboard on the backstory. Maybe there are some dry parts in your book. And maybe it would help if the protagonist got naked once or twice. But in the end, it’s up to you. It’s your story.
It’s quite possible that your beta readers don’t represent the rest of the population well. Maybe they’re the only ones that think it’s weird to set your story in the Middle East. And if you give Grandma your Sci-Fi novel, she may not like it. But that’s not an indicator of what the rest of the population thinks about your book.