I own no bike in NOS condition, but a few showpieces... they all get ridden, nevertheless. Some maybe only once a year, but still i ride them. Of course, when the weather looks wet, i take my beater, and i put most of my mileage on that and on my 'good' modern bike.
I'm not dogmatic about it, though. If someone prefers not to ride a bike that he spent a long time assembling all the nice nos parts for it, its fine with me. Its just not my way of doing it...

i once saw an elderly british couple that had driven a pre-war Zagato Alfa on the road to participate the Mille Miglia:



i liked the car better than many of the super-restored museum pieces one can also see there, and i guess it endured the race better than many of those, too...