This was Jeremiah's suggestion to maintain road manners and yet provide more than capable wheeling abilities (my front door is about 20-30 minutes from the West trailhead for the Rubicon, depending on traffic). I figure I built 2 FJ40's (iteratively - with much trial and error)...and his shop has put out who knows how many, which is why I follow the experts advice/guidance/suggestions with this one.
As to why not link the rear too? Shop recommends stretching the body/frame to make the rear angles work (or use a competition cut to shove the axles back far enough), and I didn't want to go down that path. Though I'm looking pretty hard at a 60 series body on a shortened 80 frame for my next DD.