I had a friend like that, who was 6'2 with an absurd reach, but I am decidedly not one of those people. I have pretty short stubby arms, and I'm only 5'9. I am pretty stumped as to the origin of this huge divide between my squat and DL. One explanation, though, is that when I did strongman from 2007-2009, I stopped regular squats. I only did banded box squats twice a week, but I still trained the **** out of DL since it was quite often an event for reps or maximal strength in strongman. I picked up squatting again in September 2010 for a few months when I dabbled in Crossfit Football, stopped, and then started squatting again weekly in January, continuously. In that time my squat has gone from 440 to ~485 lbs.
So perhaps, if I keep up with the current training volume, I will have a mid 500 squat sometime by this time next year?
also, slight brag, I am within touching distance of elite in every lift except the clean, and elite in DL obv

Thanks for posting that, I needed the ego boost after a ****ty week of squatting.