It’s no more Mr. Nice Guy for the founder of hedge fund Third Point, a major investor in Sony. In a letter to his investors today, Daniel Loeb says he’s fed up with the performance of the electronics giant’s movie, TV, and music businesses — which he wants Sony to package in a separate stock, with a minority stake sold to the public. “We were surprised that after Entertainment’s highly touted big budget summer releases — After Earth and White House Down — bombed spectacularly at the box office, CEO [Kazuo] Hirai, speaking at the Allen & Co. Sun Valley conferences a few weeks ago, brushed off these failures saying: ‘I don’t worry about the Entertainment business, it’s doing just fine’,” Loeb says. Calling the films “2013′s versions of Waterworld and Ishtar,” Loeb says it’s “perplexing” that Hirai gave “free passes” to Sony Pictures Entertainment Co-CEOs Michael Lynton and Amy Pascal, who he called “the executives responsible for these debacles.” Loeb adds that he’s concerned about the studio’s pipeline, which he describes as “bleak, despite overspending on numerous projects.” And the television business “relies on old Merv Griffin Production workhorses like Jeopardy! and Wheel Of Fortune” but “has no hit network television shows, only one major syndicated network show, the Dr. Oz Show, and has missed the market for unscripted television.” Loeb says a stock offering would make the operation more transparent and accountable. “While CEO Hirai focuses on Electronics, Entertainment is in desperate need of proper supervision,” the letter says. “We believe Sony’s Board, which we understand continues to consider our suggestions, has plenty of reasons to worry about Entertainment and should enact our partial listing proposal quickly.” Loeb is an investor in Variety with Deadline’s parent company PMC.