I always thought that too, as do most people I've asked. However, last year I found a way to work a bit higher with the hands that make it 5.9, at least for me anyway. If I don't use that hold and go out way right for the insecure slabby move, it's feels very 10a.
I love Jill's but if you fall at the crux, odds are good for rolling/breaking an ankle on the bulge below so it's never a gimme in my book.