Why are these random stand users allied with Kira and Gentlemen Take Polaroids? Do they get anything out of it? And has Curtis Mayfield had Superfly for three years, or did he get it recently? Is it ever explained? Normally asking this would be too soon as it might get answered in the next episode, but this is JoJo.
It's answered, yes, but the answer is essentially the same reason for most of the stand users in Part 3: money. And I think the Superfly guy just had the stand prior to the start of Part 4, was trapped in the tower for years, and then Kira's Dad just hired him.