What’s surprising to me about the dominance of YouTube is the fact that 1) unlike all the social networks there is very little network effect with YouTube, and 2) there are perfectly to viable alternatively such as Vimeo that are routinely bypassed.
With the tvOS, you need different profiles for different members of the family. Otherwise your five-year-old ends up seeing a lot of mature TV shows in their recommendations. And the adults see various recommendations meant for small children. If you have small children and Netflix or you don’t have multiple user accounts set up you know what I mean.
This is the simple and easy solution for the tvOS because they can’t realistically expect you to purchase multiple Apple TVs for the multiple members of your family.
On the other hand, they very much do hope you’ll purchase multiple iPads.