Captain America would have loved to have helped Thor take on Hela. Unfortunately, he had jury duty,“ Waititi joked. “I was once on a jury in New Zealand where 17 avocados went missing from a local farm. We never found the culprit.”

He pointed out that while Spider-Man wanted to help, he is still in high school. “He couldn’t get his Aunt May to write a note saying ‘Peter Parker can’t come to class today because he’s on another planet fighting gods’.”

Tony Stark was busy as well, but his clothes and glasses do appear in the film.

“Black Widow would’ve pitched in with Thor if she had been free at the time, but she wasn’t free at the time,” he said, maintaining a straight face the whole time. “She was a prisoner for stealing 17 avocados from a local New Zealand farm… wait a minute.

Taika Waititi on why the Avengers couldn’t star in Thor Ragnarok
(via fyeahmcublackwidow)