Cavers are usually pretty friendly and eager to talk about caves. But sometimes there will be a change in attitude or awkward moment of silence when certain caves are mentioned. Long time cavers know this is a signal that a particular cave is sensitive and should only be mentioned in private. Non-cavers may take the behaviour to be secretive or arrogant and be slightly annoyed.
Cavers often need to protect certain caves. Gates are the ultimate protection, but require time, effort and money. Obscurity is the next best option. If no one knows how to get to a cave, then they can’t cause problems.
If a caver has a good reputation and history of ethical cave behavior then they will likely be considered trustworthy for cave locations and be let in on “secrets”.