I think they were banking on Vader hating the planet so much he’d never willingly return and then later training Luke in the hopes that Vader may hesitate to kill his own kids, because Vader hesitating to kill someone is basically the only way anyone has a hope of beating him.
In retrospect, hiding Anakin’s son on his home planet and keeping his last name wasn’t such a great plan.
I think they were banking on Vader hating the planet so much he’d never willingly return and then later training Luke in the hopes that Vader may hesitate to kill his own kids, because Vader hesitating to kill someone is basically the only way anyone has a hope of beating him.
He does hate sand!