Because of the possibility for a huge amount of success. Put it this way would you like to run a company that makes something tons of people enjoy and also makes millions of dollars? Answer: yes,yes you would.
Polygyny has several economic, social, and health advantages over monogamy. In most cultures, women contribute significantly to the wealth of the household and can thus materially benefit from the labour of an additional spouse.
His role in the First Triumvirate, his conquest of Gaul and his victories during the Civil Wars. These were the key stages in Caesar's career that allowed him to become the Emperor of Rome.