Plex doesn't allow system admins to remove them for all users - each user has to do it themselves. The intention behind the decision is pretty obvious and soured me considerably on Plex.
Uncle and Auntie won't understand that they aren't part of my library, and will complain when something goes wrong with them despite the fact that they're beyond my control.
As the person who owns and operates the service, I should have the control to set default configuration for my users. Just like I should be able to shut off all the ads for everybody, I should be able to set the default quality setting to max.
I never asked for the support burden of content that I'm not interested in offering MY users of Plex. They're not Plex's users, and it speaks volumes of their motives that they think it's appropriate to Trojan horse monetization services onto my users.