See? Another great idea by people who didn't get to write the movie.
It wouldn't be shocking, that's for sure. The film acts like Luke somehow processed being the son of a dark lord in the space of one film, had his father die in front of him and had to somehow come to peace with everything, and somehow it never comes up again ever. Yes, it's very likely his fears about the dark side and his own father being seduced fed into his fears about his own nephew following the same path... although Luke spared his father even when inconvenient, while turning on a younger person he was mentoring. It's like a huge blind spot.
It's an idea that I think they barely grazed with Anakin in the prequels. The Jedi went to great lengths to shelter him from the darkside, which backfired horribly. Not letting him go see and rescue his mother because of some bullshit rules about Jedi not having connections and attachments (a rule that seems to be inconsistently applied throughout the prequels)? They couldn't send some Jedi back to Tatooine to rescue or purchase her freedom, and set her up in a nice condo somewhere, then say, "you can't see her, but rest assured, your mother will never be a slave again, and will live out her days in peace"? But then they let him be the personal security guard to the chick that they knew he had a crush on? What again about attachments?
But all of the trauma Anakin went through as a kid (despite Lucas making him look like a happy, ordinary kid with a cool bedroom) and he was expected to just get over all of that?
The Jedi had their fears of the darkside, but maybe the darkside itself isn't evil; it seems like a real balance of the force would involve exploring both the light and dark in a healthy manner, rather than just repressing it and spewing some draconian platitudes about attachments. They constantly warn pupils of the darkside throughout the saga, yet they complain that fear is a path to the darkside. Seems like a dangerous tightrope to walk, "fear is bad, it leads to the dark. Oh by the way, don't be tempted by the darkside, it's really bad and scary."
Perhaps Luke over sheltered Ben, which somehow was what led to Ben's unhealthy fixation on the darkside. And that was because of Luke's own insecurities, maybe, stemming from the shit he went through, like you said, in a relatively short time frame.
I dunno, I guess I chalk up prequel inconsistency to Lucas being a shitty writer. But it was a MAJOR problem. And I see similar narrative and plot issues with the sequels.