I think cars should be driven. In general, if a car isn't a piece of automotive history, I think it should be taken out and enjoyed. Otherwise, you're missing out on half of what it is.
That said, historic pieces I can see spending most of their time in a garage. It's a shame to hide them away, but I understand it. However, I think they should still see some daylight at events like the mentioned Pebble Beach and Goodwood. They are still cars, and motion is intrinsic to what a car is.