After the Betamax debacle it decided it would win the next format war by owning studios.
That meant that anything it built for the consumer also had to be good for the studio. So for example it launched the excellent minidisk player (a 76Mb minifloppy) with better than MP3 quality when MP3 players were 32Mb for twice the price.
But it refused to release the minidisk drives for computers, because that would lead to piracy - so the only way to get music on the units was to buy all your albums again on minidisk (the studio's preferred option !) or record them on the microphone in. Then they did the same again with the PSP.
Suppose Apple had decided to ensure the success of the iPhone, not by making it great, but by buying a cell carrier - then limiting your calls to other iPhone users.