When news broke that Disney wouldn't push Robert Downey Jr. for Best Actor at the Oscars for his portrayal of Iron Man, fans started a petition to change that. It's clear Downey's appearance in Avengers: Endgame connected deeply with the audience, but in an interview with Howard Stern he has expressed next to zero interest in bagging the nomination.
After discussing Martin Scorsese's comments on Marvel movies, in which the director said they were "not cinema," the topic of Academy Awards nominations came up. "There was some talk about it, and I said, 'Let's not,'" Downey explained at 2:20 of the interview clip below. So it was ultimately RDJ himself that didn't want to pursue an Oscar campaign for Endgame, not Disney, as many had previously believed.
"I'll tell you the truth; I didn't expect to become what it became, and it is this very large multi-headed Hydra at this point," he responded when asked why he retired from the iconic role. "I've always had another interests. According to Scorsese it's not cinema, I gotta take a look at that, you know?" Asked why Martin Scorsese would have said that about the MCU, Downey added, "Because it's his opinion."
"I appreciate his opinion," he continued. "I think in his view, and by the way there's a lot to be said for these genre movies and I was happy to be part of the problem if there is one, where it denigrated the art form of cinema. And by the way, when you come in like a stomping beast and you eliminate the competition in such a demonstrative way...it's phenomenal."
Downey has received two Oscar nominations in the past. In 2009 he picked up a Best Supporting Actor nom for Tropic Thunder, and in 1993 he received a Best Actor nom for Chaplin. Watch the full clip from his Howard Stern interview above.