First off it is pretty quick to do a Vic belt, and it can be done on the side of the road if needed. That said the cast frame bikes are a good bit tougher then the steel frame bikes
Next comparing a HD or most of the rice cruisers that make 70-60FtLb of torque to a Vic making at or above 100FtLb; is apple to orange comparison.
Then there is the difference between the 92" belts, and the newr carbon/kevlar belts. The new belts are MUCH stronger then the early belts, and if you have a 92". Change it at or before 30K
Finally....Yes the belt replacement is interval is a little conservative on the 100/106 motors, but would you rather replace it on your tems when it is convieniant, or on the bikes terms in the middle of a long road trip.....think about it