I don't think in the past people were taking self-help advice from Heracles and Achilles or in the modern world from Neo and Luke Skywalker

I don't know how the ancient Greeks related to their legends (although I'm sure that historians of the period do, and it would be worth knowing what they say), but The Matrix and Star Wars are certainly used in that way. Just google "red pill", or "Do or do not. There is no try." And these things aren't just made up by the storytellers. The ideas have long histories.

Literature is full of such practical morality. That is one of its primary functions, from children's fairy tales ("The Ugly Duckling", "The Little Red Hen", "Stone Soup") to high literature (e.g. Dostoevsky, Dickens, "1984"). Peter Watts ("Blindsight") isn't just writing an entertaining story, he's presenting ideas about the nature of mind and consciousness. Golden age sensuwunda SF is saying "we can and will make the world and ourselves vastly better", and has indeed been an inspiration to some of those who went out and did that.

Whenever you think you're just being entertained, look again.