This was baffling to me. I've rarely had such a stressful user experience as a trailer playing every single time I stop pressing the arrow buttons for a few seconds. Just because I stopped pressing buttons doesn't mean I want to see a trailer for whatever I happened to stop on - it means I'm thinking about something, or reading something, or looking at some other part of the screen, or am not even looking at my TV any more. It's hard to imagine a more malicious UX than one that plays video and audio at you every time you are not giving input. And because it's difficult to even find a state in that UI where you don't have something selected, I found it impossible to "escape" the trailers. It made me feel like I was in an advertising dystopia.