I wouldn't argue that he isn't a legend. I just don't think he's a mainstream legend that will pull the crowds for a Glastonbury headline slot. He's not in the same category as Elton John or Paul McCartney. I'd place him in a category with the like of Cat Stevens. I think he is perfect for the legends slot but no more.
Midge Ure in Leeds last night. Doesn't quite have the vocal range but excellent musicianship and also has a bigger catalogue with Ultravox than I recall. Skipped out on his time with Silk, though he did play The Boys Are Back in Town - presumably given he had a stint in Thin Lizzy and wrote Yellow Pearl.