That's my point though, some people are using non-tapered bolts (OE button head style) with holes that are conically tapered for flat socket style bolts. And from the looks of it, they aren't having any problems.
The sprocket I took off my bike was on there for at least the 200 or 300 miles that I put on, let alone at least a few miles (probably more) that the previous owner accumulated. There was no damage to the holes (egging, galling, etc) that I can see and the bolts were all torqued properly. Surprisingly, it almost seems like it doesn't matter what style of bolt you use as the hub hole is sized very close (~+1/-1 mm). All those bolts do is just stop rotation and the minimal shearing forces from hitting things while offroading.