1. Authors are creators and therefore producers. That's a business, even if they aren't expecting monetary profit. It's negligent to put something so destructive into place, without even thinking through the consequences.
2. Has nothing to do with honesty and everything to do with decades of experience in data analytics and UX. It would take someone 1 hour to create a script that just spits out fake ratings from random npubs.
3. Once you get everyone used to the 5 ⭐ system, you can't roll it back in your app.
4. The ratings are only useful, if there are a lot of ratings. The thinner the volume of the ratings, the easier they are to game. That's why a lot of websites actually hide ratings until they have at least n number of high-quality ratings on the item.