Quentin Tarantino explained via a press conference:
Frank Ocean wrote a fantastic ballad that was truly lovely and poetic in every way, there just wasn't a scene for it. I could have thrown it in quickly just to have it, but that's not why he wrote it and not his intention. So, I didn't want to cheapen his effort. But, the song is fantastic, and when Frank decides to unleash it on the public, they'll realize it then.
Ocean's poetic wordplay has been monumental in the art of song writing. "Wise Man" has managed to eclipse his previous works with an in-depth look at the duality of man and the vital force that fuels the will of action for humans.