It was much worse than just adding it to your library as a gift. The cover art for the album[1] would appear in seemingly random places on your phone. And there was literally zero way to remove it, until there was such an uproar that Apple had to make a special tool.

Apple spent money on this and they really, really wanted to force feed it to every Apple user (not unlike their F1 movie venture). It was incredibly obnoxious.

1 - And it isn't homophobic to note that the Songs of Innocence cover art looked a bit like you were browsing Grindr or something. People have the right to have the opinion that having that image suddenly being featured on their phone might be misinterpreted by others.