This is a kind of revisionism that mostly took off after Warren Buffet won his bet that hedge funds would not outperform the market over a 10 year time period.
The original goal and selling point of hedge funds was to produce consistent results regardless of the market's performance by using long and short positions to provide absolute returns in any market environment.
With that said, even if you accept the revisionism, it's untrue that actively managed funds are uncorrelated with the market. What is true is that selection bias makes it seem like they are since when interest rates rise and markets go through a down swing, the majority (and yes I mean more than 50%) of hedge funds go out of business. As such the only hedge funds that remain are the ones that happened to weather the storm so to speak.
The original goal and selling point of hedge funds was to produce consistent results regardless of the market's performance by using long and short positions to provide absolute returns in any market environment.
With that said, even if you accept the revisionism, it's untrue that actively managed funds are uncorrelated with the market. What is true is that selection bias makes it seem like they are since when interest rates rise and markets go through a down swing, the majority (and yes I mean more than 50%) of hedge funds go out of business. As such the only hedge funds that remain are the ones that happened to weather the storm so to speak.