Some professions seem especially prone to this priesthood mindset. Inward-looking, amplified self-regard, and dedicated to a mission that nobody asked them to take on, because the new mission is more gratifying and ego-boosting.
Some software engineers do this — devoted to some abstract notion of code cleanliness or architectural purity that has no obvious relationship to delivering working software that is useful to others.
This is not even rare or just in niche professions - this is everywhere, and perhaps even the default if not actively fought. I always found it dishonourable myopic.
Nietzsche said that the priests are the enemies, and I'm starting to think he was on to something.
In the museum case, the preservation role is explicitely asked for. It is one of official reasons for muaeum existence.