Another clue may come from the meaning of the name Zerubbabel: The name Zerubbabel consists of two parts. The second part of this name is obviously the same as the Hebrew word for Babel / Babylon. The origin of the first part is a bit of a mystery.
Insubordination is generally a punishable offense in hierarchical organizations which depend on people lower in the chain of command doing what they are expected to do.
It was an example of shop talk in the workplace. Insubordination is generally defined as a willful or intentional failure to obey a lawful and reasonable request of a supervisor. It may also be an action which constitutes lack of respect or harassment directed toward a supervisor.