Short answers, pulled from the story.
Gary Kurtz was an American film producer born on the 27th of July, 1940, and died on the 23rd of September, 2018. His major production credits include American Graffiti (1973), Star Wars (1977), The Empire Strikes Back (1980), The Dark Crystal (1982), and Return to Oz (1985).
Kurtz claimed he left because George Lucas shifted the franchise's priorities toward toy merchandising and commercial entertainment after Raiders of the Lost Ark in 1981, moving away from the darker, more story-driven ending originally planned for Return of the Jedi. Opposing accounts state that Kurtz was fired by Lucas due to his mishandling of The Empire Strikes Back, which went significantly over budget and schedule.
American Graffiti cost $1.27 million to produce and market and returned more than $55 million in worldwide box office gross on its first release. Universal reissued it in 1978 and earned an additional $63 million, bringing the combined total to $118 million. By the 1990s, box office and home video receipts together exceeded $200 million.
Kurtz was the producer on The Empire Strikes Back and also helped direct alongside Irvin Kershner, David Tomblin, Harley Cokeliss, and John Barry, who died of meningitis during production. The film took 175 shooting days against an original budget of 100, forcing Lucas to borrow $10 million to complete it. Kurtz was replaced by Howard Kazanjian four weeks before filming wrapped.
Kurtz served in the U.S. Marine Corps from 1966 to 1969. Raised as a Quaker, he enlisted as a conscientious objector and refused to wear a sidearm. He served as a combat cameraman in Vietnam.
On its international release in 1983, The Dark Crystal was the highest-grossing film of the year in both France and Japan. It out-grossed E.T. the Extra-Terrestrial as the most successful foreign film in Japan until Titanic displaced it fourteen years later. Its domestic U.S. box office total was $40,577,001, above its $15 million budget.