Both the next-gen UIs are kind of cruddy. I think the Xbox One is taking much more heat though because it's a lot more complicated to move around, especially without reliable voice controls. The Xbone has more features than the PS4, all hidden through layers and layers of menus that look confusing to navigate. The PS4's one-dimensional bar isn't great either, but that system is simpler to use, so it's not too awful.
Yeah. I think the main problem is that the Xbone's UI is just layers of crap on crap. PS4's isn't super sexy but at least I don't get hit in the face with ads while I'm trying to find settings.