It’s because (as I’ve mentioned earlier) the Left doesn’t have a sniper hero that was killing American soldiers ....and they’re so upset ....
They did have one - He was killed by Kyle in the movie.
Fictionalized account. Don’t remember it in the book.
The left insists on “shades of gray” instead of hard black & white, good & evil.
Because, when judged against the standard that puts you on one side or the other, their beliefs, actions, etc, always fall on the evil side of the line.