The ads on the UI, to me, betray an unwritten agreement regarding ads. In the old days you bought a radio and a TV and the content was free. It just being broadcast over the air and if you have a device that could grab the signal, you got it for free. But someone needs to pay for these radio and TV shows and that's where advertising came in. The agreement was that our content would have a bunch of annoying ad bullshit in it, in exchange for it being free. We later accepted the same conditions on the internet - I will put up with your ad bullshit if I can access your web site for free.
But I don't get Xbox Live for free or an Xbox console - but I have to put up with ads. Uh, what the ****? That's not the agreement. You're not supposed to get ads for stuff you pay for. And there's the offensive nature of it all. The public and advertisers had a mutual agreement of ads being in exchange for free content. But the advertisers look at it more like "what can we put ads on?!!" as if the whole world is just a big blank canvas for their intrusive bullshit.
My priority for a UI is to get to where I want to go ASAP. I know if I want to play a game or use Netflix or go into the online store before I even turn the system on and if I can't get there immediately with minimal effort your UI SUCKS. However has the best usability:bullshit ratio wins.
The Xbox dashboard looks like the TV in Idiocracy.