Yes, you are telling the truth. Restricting the game itself can cool the players from the game and the story.The problem with all of that, is that if there is no harem, it becomes moraly reprehensible to pursue other women than the selected ones from your path, past a friendship phase, while being in a serious or developping relationship with the selected partners.
From that point of view, the actual content of the game would actually become quite limited, and leave an empty feeling. Or you could pursue all women at once, have intercourse with all of them, and be a manipulative asshole.