I basically never see Plex adverts (and I only use local streaming really). Where do you normally see them?
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 can't do either.
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.