Again there is no technical rigor behind these notions. Video providers didn’t like the idea of untrusted HDMI devices scraping video from DRM protected content so they came up with HDCP, which allows anyone to develop and certify solutions as trusted software/hardware. There’s no reason apple can’t do something similar, it doesn’t have to be completely open vs. completely closed. There are always alternative solutions to the problems that people think apple’s walled garden approach is solving; which makes it clear what the real purpose is.