Why Diana: The Musical Is So Controversial

Diana: The Musical is controversial largely because it attempts to turn Diana's real-life into a fun romp without really acknowledging the tragedies of her life.
Diana dances in a Madonna-style wedding dress, hoping to make Charles "a rocker."
There are 21 songs in Diana: The Musical, and none of them really highlight the struggles that were a key part of her life.
This said, one of the reasons the film has been accepted by some is because she is such an iconic figure.
This film plays with the image of Diana as the fun-loving celebrity some remember.
Many want to think of the song "The Dress" in Diana: The Musical as truth.
Diana was a fashion icon.
She was known to be cheeky, once remarking to Tim Curry that The Rocky Horror Picture Show "quite completed [her] education."
To this group, this film is a love letter to how Diana wanted to be seen, and thus doesn't need to fully reconcile with the darker parts of her struggles.
The problem with Diana: The Musical is that the legacy of Diana is a complex one, especially given the deep emotions many still have for her.
There are those who think this fun film makes light of all the adversity Diana faced in her life.
There are others who think Diana herself would have enjoyed this.