I have learned something over few years building tools for my startup and friends. You should identify constructive feedbacks and the one designed to tell everyone: stay away from this product. You should make an effort to respond vigorously to the latter so it does not suck out all the oxygen out of your product existence.

Your response here tells everyone: yeah his right you should come back when I have made the magic work according to this guy. What you don’t know is that the guy will criticize you anyway because he is actually criticizing your existence. My take is you should not let that happen.