I like a lot of what Robert Kiyosaki says usually and there are serious problems with a lot of mutual funds, but the basic point in his column on Yahoo's website is plain wrong. He says that if a mutual fund earned 8% a year and charged 2.5% in fees (the first number is plausible as an after inflation return on a long stock mutual fund, the second number is high but not totally implausible) then your after fees return is 5.5% which means that over a 65 year period $1000 would grow to $140,000 if there were no fees but only $30,000 after fees. So far so good. But then he says that this implies that the fund manager makes 80% of the return and you only make 20%. Not true. You make 21% of the potential before fees return but the fund company only makes 10% of the potential return ((2.5*30,000/5.5)/140,000). 69% of the potential return just disappears. So it is just as bad as he said but the mutual fund company isn't benefiting from this. The idea that if you lose someone else must be gaining is a common myth among investors - many people think that if the stock market goes down and investors who own stocks lose someone must have gained. Not true - a few short-sellers do gain, but most of the value just evaporates.
The truth about mutual funds is that actually fees don't matter. Fund companies like Vanguard who have low fees would like you to think this. All that matters is your net return after fees. If the return after fees is better than you can do on your own after taking into account the value of your time you would rather spend on something else then the mutual fund is worth buying and otherwise not. You could just buy an ETF invested in a stock index. If an actively managed mutual or hedge fund returns after fees more than this investment then it is worth buying. I find that in very strong trending markets, passive investing beats active investing. In weaker markets active investment seems to win out even after fees. Last year in the US active funds beat passive funds. But in Australia the opposite was true. In the 1990s, active investing won in Australia and passive investing in the US.