It can be hard to find a beta-reader who will show you what you might have missed on your novel or if you wrote something that doesn't fit in a specific scene but still maintaining professionalism while doing so. Although it is hard to be blunt to an author about these things, being too forgiving can also lead the author into a false sense of security where they would not be used to having another beta-reader.
I know that every novel created is a novel touched with passion and love, that's why I am keen on helping authors polish their novels with utmost respect while still keeping an eye out for every plot holes and inconsistencies found in each character's voice.