NEW YORK ( TheStreet) -- Bill Ackman's exit from J.C. Penney's ( JCP) board of directors isn't a death knell for activist investing. Ackman's departure from J.C. Penney comes after his hand-picked CEO Ron Johnson failed to turn around the struggling retail giant, and the hedge funder waged a losing war over the company's management and strategy. Many now wonder whether J.C. Penney can make it past the holidays, after spending billions on a failed store revamp that drained the company's cash coffers. J.C. Penney elected retail industry veteran Ronald W. Tysoe, the former vice chairman of what is now Macy's ( M), to the company's board on Tuesday, a move Ackman said he supports. The hedge funder's retreat at J.C. Penney comes as his nemesis, Daniel Loeb of Third Point Capital Management, was forced by Hollywood icon George Clooney to backtrack from highly critical comments he made to Sony's ( SNE) management. Loeb owns about $1 billion in Sony shares and seeks to spin off the company's movie studio business in an attempt to revive the struggling electronics giant. Carl C. Icahn, the dean of modern day activist investing, meanwhile, faces the imminent prospect of failing to win over Dell ( DELL) shareholders on a competing bid to what could be one of the biggest leveraged buyouts in history. Ackman, Loeb and Icahn are all intimately connected to a drama at Herbalife ( HLF). Ackman has bet $1 billion that the company is little more than a Ponzi scheme. Loeb and Icahn have publicly taken the other side of Ackman's trade and have, so far, made millions of dollars in profit. "New HLF product: The Herbalife Enema administered by Uncle Carl," Loeb wrote on his Bloomberg profile in July. Clearly, a crass breed of barbarians is storming the gates of Corporate America. What board would let them in? The answer is that while Ackman, Loeb and Icahn may be pushing the limits of good judgment, they will continue to have a significant influence on markets. Ackman, after all, remains an independent director on Canadian Pacific's ( CP) board. Meanwhile, the hedge funder has recently made a play at chemicals giant Air Products ( APD). Loeb can count a turnaround at Yahoo! ( YHOO) under new CEO Marissa Mayer as a major recent activist success. Loeb, at times, resorted to crude tactics such as publicly shaming Yahoo!'s former CEO Scott Thompson. With hindsight, the company's shareholders are likely to view such actions as necessary. Carl Icahn helped to pull Chesapeake Energy ( CHK ) from the brink of bankruptcy after building an investor consortium on the embattled oil and gas driller's board. Analysts see Icahn's influence as helping impart Chesapeake's management change and its execution on needed asset sales and capital expenditure reductions.