“When one door closes another door opens; but we so often look so long and so regretfully upon the closed door, that we do not see the ones which open for us.” –Alexander Graham Bell
The same can be said about our stories.
We spend so much time coddling our babies that we lose the ability to see the most obvious flaws or to draw on inspiration outside of our own heads. Familiarity breeds myopia. It’s not your fault, it’s the nature of the beast. A good way to get around this lose of perspective is to let someone else take a peek under the hood.
Getting an outside opinion can allow you to see things that you would have missed had you struggled away all alone.
When it comes to opinions, what you need to balance is the desire to hear what someone else has to say against your vision for the story. Sometimes you’re wrong and you need to admit it and make the necessary changes. Sometimes, you’re right and you need to take the opinion for what it is and hold fast that your position.