The reason I believe why Apple TV hasn't quite taken off is because most people like having their cable and Apple TV as an extension to more viewing option. Apple wants to aim to replace cable boxes and to do so, a revamp is required.
Now the company has released the third beta of tvOS 9.2, the next update to the Apple TV, and it looks like it will address many of the shortcomings users had complained about in the software, notes MacRumors. For starters, tvOS 9.2 will add Siri dictation support to the Apple TV. Many have been frustrated that while you could ask Siri queries or tell Siri to perform actions like opening certain apps, a basic function of Siri on iOS–-the ability to dictate words and have them typed on screen for you–-had been left out of tvOS. As of tvOS 9.2, that feature has now been added, and it will make entering service login names, passwords, and other text much easier on the device, especially considering that not many are fans of its horizontal on-screen keyboard.
Another major feature that tvOS 9.2 will introduce is Siri App Store search. Currently you can ask Siri to find TV shows and movies, but not apps. With tvOS 9.2 you’ll be able to use Siri to search for apps or app categories by voice.
Now if Apple delivers upon these improvements along with many more, their flagship TV device will perhaps penetrate the cable viewing market harder than it has before.
link: http://www.fastcompany.com/3056504/fast-feed/the-apple-tv-is-about-to-get-much-better