Please help with homework The Mousetrap: Agatha Christie and for over 60 years

Agatha Christie and for over 60 years the play’s producers have made an anti-spoiler request: “Now that you have seen The Mousetrap you are our partners in crime, and we ask you to preserve the tradition by keeping the secret of whodunit locked in your hearts.”
How much of the appeal and fun of a murder mystery is figuring out or discovering whodunit? If you knew at the start, would the experience be the same?
Compare it to knowing the result of an important sports event before you watch it—do you watch the same way? Do you watch at all? Should we respect the no-spoiler request? Is it part of the art? Is that fair?