Why? Because of the emotions and meanings we attach to money.
Money is still a Taboo subject. In 1913 Sigmund Freud wrote, “money questions will be treated by cultured people in the same manner as sexual matters, with the same inconsistency, prudishness and hypocrisy.”
I think his observation is still applicable today. Look at this NY Times article
Lynda Moore http://www.mymoneyseeker.com