My take is more along the lines of either making a little value bike more usable (my wife's Univega) or upgrading a lifetime bike to make it even better. If the bike is one if those special rides, but the time has come to go to brifters or wider gearing, it is something I would do; it will just bring many more enjoyable miles.

If it is just a collectible bike, but not a love-to-ride bike, probably not.

John