Third-party stuff isn't sufficiently sticky. If Apple wants games on their platform, they need their own controller. It might even be best if it comes in the box.
I don't, however, think they really care that much.
It absolutely needs to come in the box for it to be effective. You need to be able to rely on 100% of your customer base having the hardware required to play it.
The thought that they don't care that much is really strange, because every single keynote that I can remember has included game demos. They always use game demos, from AAA game developers like Epic, to come out and show off the latest capabilities. They could take a sizeable chunk of PS4 and Xbox One customers very easily - fund the development of some genuinely AAA, exclusive games, bundle the controller in the box and the thing would sell like hotcakes. Nintendo is somewhat safe because their IP is much more valuable than Xbox or Sony, who basically offer the same games with a few notable exceptions.
I don't buy that the logo alone would do it. It would have to come bundled with a controller by default and all games would have to work with said controller.
Games compatibility is key. I had an Android phone I used years back with a PS3 controller and an external display to play Modern Combat 3 and it worked great as a game console... except every now and again the game forced you to swipe the screen to perform some quicktime action. Really unexpected when you're sitting 5 feet from the screen.
I don't think gamers necessarily expect an L3/R3 button. The Switch does not have anything like that, and Nintendo has always been top tier for gaming controllers.
I've been tinkering with some commits to get the Moonlight project working on tvOS, and the biggest stumbling block to many of the games I could play with a controller is the lack of L3/R3 buttons. Sprint, look behind, crouch, take cover, melee, etc. all get mapped to these buttons pretty frequently, since your thumb is generally resting on at least on of those sticks during normal play.
Nintendo has historically terrible controllers which started with the N64 controller. That didn't end until the pro controller for the Wii U/Switch.
Even the switch joycons, which I think are incredibly impressive with how much tech is crammed into them, are pretty awful to actually control with. The only reason I think they get a break is because they are designed for portability.
