This is not the first time that hedge funds’ influence over markets has come in for criticism. Characterized as the Masters of the Universe in the 1980s, they’d taken a chunk of the business of old-money bankers by the mid-2000s with the sheer size of their investments.

Now, hedge funds are losing market share along with other active managers as their $3 trillion industry is pilloried for high fees and under-performance by critics ranging from anti-capitalist protestors to billionaire Warren Buffett.

Singer, the founder of Elliott Management Corp., warned of the dangers of passive investing in a letter to clients last month, saying it damages markets because it doesn’t discriminate: If bad companies attract investment along with good companies, he said, there’s little incentive for them to create shareholder value.

The Elliott boss, whose main hedge funds manage $33 billion, is well known for his high-profile activist wagers, and argued that passive investing is  a “blob,” whose practitioners aren’t really “investing” at all.

FCA Report

Active money managers who contributed to the Financial Conduct Authority’s recent study of the $9 trillion U.K. asset-management industry echoed these complaints. They told the regulator that the popularity of passive investing risks allocating money to larger companies at the expense of smaller ones that are less represented in indexes.

They also warned that hedge funds’ involvement in price setting is “leading to larger divergences between prices and long-term values,” according to the June report.

Yet critics of active management characterized the industry’s complaint as an attempt to mask its failure to deliver value and retain clients in a market where unprecedented quantitative easing is damping price swings while sending stocks to record highs.

“It’s the last roll of the dice,” said Alan Miller, founding partner and chief investment officer at London-based wealth manager SCM Direct. Miller is a well-known campaigner against hidden fees in the industry, while his business partner and wife, Gina, recently came to prominence by taking the British government to court over its Brexit plans.

“The active asset-management industry is obviously under huge pressure because its performance has been disappointing for a long time,” he said. “It’s trying to cling on, with a feeble excuse to justify its existence.”