It's more complicated than that - as the article says PE can be used to diversify an investments. If you have a few extra billion you might not want to tie it all to the performance of the US equity market. So PE doesn't have to beat the S&P to be attractive if the ups and downs happen at different times to the S&P.
Then there is also the question of fees, if the fund is beating the S&P by 1-2% after fees, and their fees are 2 and 20 then the strategy is significantly beating the market. The problem is that there is so much money chasing PE, and that leverage means they don't need that much in client funds, that there isn't a push to lower fees that you see in the equity market.
Then there is also the question of fees, if the fund is beating the S&P by 1-2% after fees, and their fees are 2 and 20 then the strategy is significantly beating the market. The problem is that there is so much money chasing PE, and that leverage means they don't need that much in client funds, that there isn't a push to lower fees that you see in the equity market.