Most ordinary people - and I include the Rich and SuperRich in this category - are not really trained or qualified to manage their Financial Affairs, let alone their Investments. One would not expect them to as we all lead busy lives with family, work and other - maybe more interesting hobbies than checking on your portfolio every day.
As Financial Advisers handle the Investment affairs of the majority of people it is essential that their performance is checked in a professional and unbiased way.