Yes, but Luke had got over with much dark situation like I've pointed out, he's not gonna fail for that without enough buildup.
The old Jedi are stubborn, they caused their own downfall and still tried to let Luke kill Vader, Luke is the hero because he was able to see what they couldn't see and do what they couldn't do. That's the whole point of the story. Pair him with the old master simple destroys all these previous characterization of Luke and the meaning of the story. Also remember Palpatine was the Sith Lord, he did tons of evil already. Ren was entirely different here.