Why are rock biopics so hard to get right?

Look at what happened when Focus Features released a clip from the Amy Winehouse drama “Back to Black” on social media. The response was brutal. “This is actually insane,” one X user wrote about footage of star Marisa Abela singing Winehouse’s early track “Stronger Than Me,” in a montage that demonstrates the troubled singer’s rise to fame. That one post set off a wave of judgment that included comments such as, “This isn’t Amy Winehouse, it’s Amanda Whiteclaw.”