it's a kinda artificial distinction but the filesystem behaves differently in that it treats soft links like some kind of file in itself, where the hard links ARE the file itself, but deleting it doesn't affect the other reference, writing it does.

if an event has a d tag on it, and you make two events that point at it with an a tag, then that's really just like a hard link... IF the "file" is a replaceable event, so the reference to it is not to the event ID but to the kind/pubkey/identifier

the analogy breaks down at this point