Thanks to The Playlist for drawing my attention to Richard Schickel's piece on the making of "Raging Bull" in the current "Vanity Fair" . Scorsese has never attempted to hide his personal problems during 70s and 80s, but Schickel does a good job of showing how they contributed to his commitment to make something more than a conventional sports film.
One important and rarely mentioned detail is how producers Chartoff and Winkler had to dangle the carrot of "Rocky II" ("Rocky" had been a popular and even well-reviewed film, but was not yet a sequel-producing-franchise) to convince United Artists to back Scorsese's film.
I suspect, however, that Schickel overstates the failure of "New York, New York" as a factor in Scorsese's personal bottoming out at the end of the 70s. Yes, "New York" was a commercial disappointment, but United Artists was still coasting on its reputation as a director's studio. As hard as it is to believe, the era of judging films solely by their opening weekends hadn't yet begun.
(One minor error in Schickel's account: "Home Movies" isn't one of DePalma's "earlier" films; Produced as a class project for his students at Sarah Lawrence, it was released in 1980 - the same year as "Raging Bull.")