See, that's what Star Wars is all about. Seeing the heroes struggle on in the face of overwhelming odds. Johnson changed the whole narrative and feel to these movies. At the end of TFA you were anticipating Luke's return to see how the story would continue and right a wrong and fight on to save the galaxy from oppression. Even pass on his knowledge to a new future, just like Obi-Wan & Yoda did to Luke. Instead he tosses his lightsaber away, symbolic of Johnson tossing away everything we've seen and felt and hoped would continue in the saga of Star Wars. "This is not your father's SW kiddies". We already saw Anakin fall in the PT, and instead of Luke breaking the mold and not giving in to his fate like his father, he should've fought on. I guess kids can learn that fate is inevitable and dictated by the actions of our parents, so why try to find the strength to break a bad habit/mold. The Emperor said it was Luke's destiny to take his fathers place at his side, I'd rather have seen that than the cowardly limper off to a secluded island on an unknown planet to die scenario..
Yes, see, they keep fighting. Yet somehow you enjoy that Luke gives up? Oh, yeah he comes around in the end with his force projection non sense and saves the day from across the galaxy. It's a cheap and meaningless cop out and on screen death.
Maybe I'll buy into your reality fantasy of heroes falling and Luke's tragic heart wrenching character ending, when Rey succumbs to the the same fate in Rian Johnson's new trilogy, and she too becomes a fallen hero after seeing all her hard work and fighting lead to nothing....
If you believe that's a story arc for Rey's future, then I have a bridge to sell you for a great price....