While there is nothing wrong with putting a bike on display and not riding it, Isee nothing wrong with using the same. If a bike is so valuable and rare as to preclude its use, I couldn't afford it anyway. To one degree or another all of my bikes are ridden. My wife would say not enough in some cases as she is of a more practical bent. Having dropped many a rider on a Masi/Cinelli/Colnago/whatever while riding such lowly mounts as a Gitane TDF, I am inclined to think that the rider and his skills count for more than the technology that he uses. (and nowadays I sometimes find myself passed by sprouts on mountain bikes) If that were not so, I wouldn't bother with my classic bikes. I would invest in a new bike every few years and own fewer bikes.
Paul Patzkowsky Longmont, Colorado