Why would primogeniture encourage migration to colonies

Primogeniture would encourage migration because it only allows power to be given to the eldest, or first born. People who are not of the same mind of their eldest kin would want seek new territory in order to establish their own form of beliefs and display of power.

Where are the statements, only the paragraph is here

One was to hold a leash on a despot and future despots to come, another was set to ensure no despots ever came to power.