@Marsimaxam, Most successful marriages embrace wabi-sabi. (Sorry, it was hanging there.)
This question also applies to many collections, originality over completeness. A watch has fewer bits that decay, the lume, paint and even crystals and oil, but they still decay.
Certain bits are accepted as maintenance, such as oiling the watch and the crystal. But the lume is not. Perhaps because it was not originally designed to be replaced to extend the life. Maybe that is why we question the originality of the lume but not the crystal. Plus the lume is more integral to the ascetic.
Going back to preference, I too do not care for mold. There are enough choices without mold so I pass. Would I prefer a beautiful relume versus a moldy lume if all other conditions are equal? That's tough. The older and more rare it gets will throw the weight towards the moldy lume only for something hard to find.
Thinking through this (just for me), this follows a natural cycle in objects. At some point, that old chair gets refinished. It's been in the family for a long time and is getting worn. One less original chair. Over time there are fewer and fewer chairs until there are only a few known left. Sure the caned seat is gone or the leather back has all but disappeared, but it's original. Watches are not much different than other collectibles. The combination of beauty/asthetics and history/rarity equals the allure in vintage.
But there are still alot of watches. In summary, a well done relume is preferable to significantly decayed lume. Nice original is preferred to above all. One person's opinion.
I am looking forward the the thread on rusty hands.