It's not worthless - derivates have an important function in reducing volatility. But the rewards for being a merely competent derivatives trader are wildly disproportionate to the rewards for being competent in some other challenging field (eg nursing, as mentioned int he article). It's a classic example of rent-seeking.
I think history (2008 in particular) has shown many times over that they do anything BUT reduce volatility... Shielding or obfuscating possibly, but reduction in the long term, has not been their strong point.
