Private User - you are correct of course, you can decide within your main family group for profiles managed by you (up to 4th great grandparents) which profiles are private and which are public.
There are several approaches to take when you have a notable person in your family -- one is a standalone Master Profile that is not in your tree, or is connected only to deceased, older generations. The other is to have the notable profile, but not other profiles, be public and potentially be made into a Master Profile. That is up to the individual manager, the path that they take.
If there is family information shared in the About Me, the second approach is better. If the About Me is purely about their accomplishments and they are in the public, some managers choose to make the notable profile public.
As you said, it is your decision. Robin is doing a great job and there is certainly nothing wrong with contacting profile managers asking if they are willing to make a notable profile public. Many managers are happy to do so.
Thanks for your comments.