I think it’s “public” in air quotes - technically non-Cruise employees have taken rides, but it doesn’t seem like they’re pulling people organically from the waitlist. It’s mostly local influencers or Cruise investors in the few videos I’ve seen that aren’t Cruise employees.
They're pretty limited by the number of vehicles they have available and resources to support them. Even employees have trouble accessing the program due to the lack of vehicles and the waitlist is in the tens of thousands of people. I imagine they prioritized influencers or actual users since they can't possibly meet total demand.
People who have zero connection to Google or Waymo have gotten in the program and used the service for months. Waymo also removed any sort of NDA allowing people to post videos of the full experience, hence all the videos on Youtube. Lastly, I would still say "10 PM and 6 AM at a maximum speed of 30 MPH" is quite a major restriction compared to what Waymo can do.