I think there's some confusion. There is a difference between having moral value and a story having a specific message we might call a moral. A story can have moral value without preaching anything in particular.
A commitment to truth is a moral thing. But if I have to beat people over the head with the message that, for example, the bombing of Guangzhou, the Babi Yar massacre, or the dumping of crude oil into the Persian Gulf are evil, they probably wouldn't understand that or care anyway. If I have to reiterate what the Act of Congress said about the WASP facing injustice and inequity and tell people flat out that racism and sexism are wrong, that won't convince those who disagree. And right or wrong, that veers into propagandizing, which I won't do even though obviously I believe all these things are wrong. I think most people are capable of learning enough by having to empathize with the people whose stories I share.
I think when a story has moral value but no single specific moral, people can derive more than one valuable lesson from it or just have a great time reading it, whatever they want. They might even get a different lesson every time they read the same story. Excessively heavy handed moralizing rarely makes for good reading, anyway.
Then again, I also generally prefer more subtle, less heavy-handed storytelling anyway.