I cannot watch the "top movies" in the iTunes store unless I first buy them. I have also seen ads for the Showtime add-on in the Hulu topshelf, which you can't use unless you pay extra for it.
You can't "move it from the topshelf". The app decides what shows up there.
I believe what he's getting at is, a) the only apps that display associated content in the top banner area on the screen are the apps in the top row, and b) what apps occupy that top row is entirely up to you. If the information they choose to show in the top row doesn't suit you, you're free to put other apps in the top row instead.
The only Apple app I still have in the top row is the Music app, and as an Apple Music subscriber, there isn't anything they show there that would cost me extra to play. Netflix and Hulu, also in the top row, haven't shown me anything I couldn't watch, and often something I've been watching is displayed, so picking up where I left off is one click away.
By comparison, from what I remember of Roku (I have a version 3 around here somewhere), they showed me ads where it was clear that I was not the owner of the device, I was the product that was being sold to other companies, who in turn hoped to persuade me to buy some random other thing, with no way to opt out. I was a bit appalled, honestly. I mean, imagine if you bought a new Mac, and started it up and there was a window on the screen that you couldn't hide or cover, that kept trying to sell you beer, or razor blades, or diapers or something. And Apple's position on the omnipresent ad window, which had never been mentioned in the promo materials, was "well, yeah, of course
that's there". Amazon has Kindle models that are partially ad-supported, but they're pretty up-front about, "this model is cheaper because it will displays ads when you're not using it", while Roku just feels like its perfectly okay for them to put ads on my TV screen, cluttering up the interface, using space that would be better filled with useful and pertinent information.
The Amazon FireTV has recent things and things that are free-because-you-have-Prime, on the home screen, but they also have numerous rows of TV shows, movies, and apps,
for sale, right on the home screen, and an unremovable, changing, banner ad at the top for a movie they want to sell you. They intermingle, on the screen, things you own or already have access to (because they're free or included with Prime) right next to things that cost extra, because it's a way to make money off of you. It's centered around media that you already have or they'd like to sell, and apps are treated as just another kind of media. (I have a FireTV because it was on sale - Black Friday or some such - and I already have Prime, so it was a way to see Amazon's Prime Video - I don't use it much.)
On the Apple TV, the screen (aside from that top bar) is filled with app icons that are there because you've put them there, or you've chosen to leave them there, and the only things that could possibly present ad-like stuff on the top of the screen are apps in the top row, which you have complete control over - you can stuff any apps you don't care about into a folder and never look at them again, if you want.