What ROTJ lacks is that great scene that gives you goosebumps.
SW goosebump moments:
-Luke looking at the charred remains of Owen & Beru and realizing his destiny
-Luke looking at the Binary Sunset
-Luke & Leia swinging across the Death Star to that great John Williams score
-Obiwan smiling at Luke as Vader cuts him down and Luke screaming, "NOO!"
-Han telling Luke, "You're all clear kid!" and Luke blowing up the deathstar.
ESB:
-Yoda lifting the X-Wing to that great John Williams score
-Han telling Leia, "I know." then being frozen in carbonite while Leia stares Darth Vader.
-Vader telling Luke, "No, I am your father!"
-The ending of ESB as Lando/Chewy fly away and Luke,Leia, C3PO and R2 stare out at the galaxy.
I honestly can't think of any scene in ROTJ that gives me goosebumps, there are great scenes like the Throne Room scene, but nothing that gets me like SW & ESB, that is the difference as to why I think ROTJ is the worst.