I posted something similar in a different thread...
On average, Hedgefunds have the tendency to not make a lot of money, because they either trade against long-term-buy-hold AND against themselves.
The against themselves part means that that bit is a zero-sum game.... One HF buys, the other sells short... both together don't make anything... they actually lose on fees etc.
So in a bull market, WB will always outperform the total/average HF. And since I don't think there has been a 10 year bear market... or a bear market without a decent bull market as follow-up in a 10 year period, that's just a dumb bet to take for the HF or whoever was at the other side of the Buffet-bet.