When Apple released their new Apple TV and tvOS last year, the initial documentation said that apps for for the new platform could require a game controller to play. Such apps would only appear in the store and be downloadable for users who had connected a game controller. This seemed like a great implementation since it would protect users without controllers from being confused by apps they wouldn't be able to use, and it would allow games to be designed from the ground up for richer input schemes. But just 24 hours later, Apple had changed the documentation to require all apps and games for the Apple TV to support being played with just the Siri remote.
Every console and portable gaming system since 1985 has used controllers with at least two buttons and a d-pad
The Siri remote is basically a d-pad plus a single button. This means that is has less possible inputs then the original GameBoy or NES, and that games for the Apple TV cannot require more than one button for their controls. If you think of any great game you've ever played on a console, I'm going to bet it used at least two buttons, since pretty much every console and portable gaming system since 1985 has used controllers with at least two buttons and a d-pad or analog stick.
Sadly, this mostly killed any potential the Apple TV had as a home console replacement. Because a game must be playable with a single button to pass App Store review, there is no point in designing a game that could use input from multiple controller buttons since the same game would also have to map to a dPad plus one button only. In fact, the Apple TV, far from being a capable home console, has far more limited inputs than even a touchscreen-only iPhone, which at least allows for any number of virtual, tappable "buttons" to be on the screen.
Restoring the original approach to handling game controllers for tvOS would finally open up the gaming potential of the new hardware and allow for all kinds of deeper interactive experiences.