I think ROTJ could be cut a little more slack. Sure, not every Jedi has an evil father who needs to be redeemed, but Luke isn't like any other Jedi. They were all trained when the Jedi order still existed. There may have been a more "standardized" test for becoming a Jedi in those days. Luke is the first one to ever be trained in an environment where the Jedi Order has been decimated. His training to become a Jedi is analogous to Rocky Balboa training in the wilderness using logs and rocks and other creative uses of his surroundings. It isn't too much of a stretch that since Luke's circumstances are unique, his final test would be unique.
I don't necessarily agree with your diagnosis of that particular part of Jedi's story. However, I confess.....
I have always felt that characters jump a bit between Star Wars episodes, rather than smoothly transitioning (Luke jumps to being a full fledged Jedi, Han Solo jumps to being a fully committed member of the Alliance who's no longer a loner, etc.). These are great character arcs, but they are partially executed by using the time between episodes as a shorthand.
To some extent I do believe these jumps can be explained by the events we aren't shown between episodes (I actually like that these movies are made in such a way as to imply that the in-between time was not irrelevant; it stimulates the imagination about what happened during those times and it helps the world of the movies to feel fuller).
But that explanation only goes so far, and I have to admit it doesn't go far enough to perfectly prevent these character inconsistencies from being a flaw.
Over the years I have come to realize that there are different types of flaws a movie can have, and some types of flaws make it impossible for me to love a movie whereas other types don't. The flaws of the prequels fall into the former category for me, while the flaws of the O.T. fall into the latter. I wish the only flaw in the prequels was characters taking leaps of development in between episodes; I could have lived with that. For example I could accept that 20 year old Anakin is so radically different from 10 year old Anakin if his acting and dialogue were at least at a minimal level of acceptability.
This jumping/inconsistency of characters between episodes is not something that only ROTJ is guilty of. TESB is not innocent.
I'm not trying to change anyone's mind on here, and I don't think my opinion matters more than anyone else's. I just see a need for more representation on here of the opinion that ROTJ is one of the best movies ever made, since the opposing opinion already has sufficient support on the forum. I think someone else would do a better job than me though, since I'm way better at having opinions than defending them.