That dude certainly needs to drink a cup of tea, but he isn't wrong about the exclusivity in a harem. Even using the actual definition of the word and considering the origins, a harem is a form of sexual subjugation. Harems were usually guarded by eunuchs in actual seclusion and suffices to say, they were not allowed to touch each other. This is also the case in contemporary media, including and most common in AVNs where you usually get a choice if you want to allow the women to be with each other.
As for the book, this is a visual novel so it's understandable to expect to make some choices and have some control over the story. Otherwise, there's the "kinetic novel" type.
As for the book, this is a visual novel so it's understandable to expect to make some choices and have some control over the story. Otherwise, there's the "kinetic novel" type.