Ever since being introduced in 2014’s Guardians of the Galaxy and returning in last year’s Guardians of the Galaxy Vol. 2, Star-Lord (Chris Pratt) has become one of the MCU’s most beloved characters. After Avengers: Infinity War hit theaters, though, his popularity took a hit, as many fans blamed him for his actions that enabled Thanos (Josh Brolin) to complete his mission. On the commentary track for Avengers: Infinity War, director Joe Russo commented on how the fans reacted to Star-Lord’s emotional outburst that, essentially, put half the universe’s population at risk.
“A lot of fans were upset with Star-Lord’s choice in this movie. He made an emotional decision. It’s a very human mistake, and I think what’s interesting about narrative is you learn to view things from the point-of-view of different people, different characters. You learn things about life. Thor makes an equally complicated decision.”
Source: IGN.com Avengers: Infinity War Filmmakers on Star-Lord's Big Mistake