I think I know the backstory to this:
The salt grew up amongst his friends, who were also salts. Then, one day, all the other salts decided that this salt was not as good as them at saltball (?) and decided to ignore him. The salt was insulted, and he ran away to the cave, where he remained, salty, and kept getting saltier as he sulked on the incident. Only now has he been brought back up to the surface, and his extreme saltiness slowly spreads through the community of frustrated newbies on various minecraft servers.