For comparison's sake, The Graff I made started at 1.060 and my 1 gallon test batch ended at 1.002 and the 4 gallon regular ended at 1.006 (it might still ferment out a bit more). One gallon of the 5 gallon batch is wort, the other four gallons is apple juice.
I'm making an educated (or maybe not so educated) guess, but I think ciders ferment out drier because the sugar in apple juice/cider is more fermentable than the sugars made from a wort (which could have more or less fermentable sugar in it depending on certain factors, such as mash temperature).
The other factor is the type of yeast, but with my graff I used a US-05, which is supposed to only have around ~70-75% attenuation (if I remember correctly), and I still ended up with fairly dry graff.
Just some ideas...not sure of any of it is valid.