B. B. King was one of the revolutionaries that shaped the precursors to modern rock. Delta blues was probably more important to rock than anything Elvis Presley came up with. Look at the Big Four. Look at Clapton, Page, Beck, hell, Duane Allman. It was a fucking B. B. King concert he and brother Gregg attended that persuaded them to start seriously playing music.
I mean, there are other changes I would have personally made to the list, but they are chickenshit compared to the complete absence of B. B. King.