It is an individual choice. I see it as the distance you can confidently make an ethical kill shot on the animal you are hunting.
That may be as short a 10 yards or out to 70 or more.
There is an interesting piece in Bow&Arrow mag, may 2004 about Extreme Accuracy ( STARTS ON PAGE 38). The hunters featured in this article shoot out to 150 and 130 yards in practice. The thing is these two fellows are 6'6" and 6'7" and shoot bows of 87# and 75# respectively.
The article in part address this subject and does so very well.