It is to protect the public from being misled. Imagine a website that bans every person who says red is a good color. Everyone who visits the website would be misled to think people don't like red because of YouTubes manipulation. If they have to let the public know who was banned, demonetized, and why, they will be much more accountable to the public who can then know the situation. Now imagine its not red but take into account factors like race, gender, politcal belief. You can see why this would be important.