Return of the Jedi is commonly seen as the weakest of the original Star Wars trilogy - "just a bunch of Muppets," as Dante puts it in Clerks. But let's not forget that that doesn't make it indefensible.
This is an interesting clip from a 1983 episode of Nightline, where Ted Koppel moderates a discussion between John Simon and Siskel & Ebert.
Simon has some valid points, but he's such a joyless reprobate that he makes it hard for us to wallow in the displeasure with him. Likewise, Siskel & Ebert are so good at communicating the sheer fun of the film that it's easy to root them on.