I sort of agree with him. Prequels had the world building and expanding on the lore and characters of Star Wars. It was essentially the trilogy which tried to show how the Jedi were, the politics and people in the galaxy. You know, also try to explain force, even though it wasn't needed. All those could have been much cooler if it had a better script writer and no over dependence on CGI.
This is where I disagree very strongly. I don't think writers/movies should only get a pass for attempting to explain or expand on lore. You should have a strong story focus that concisely explains each plot point that ends up being interweaved into the OT.
The politics of TPM felt like it was going nowhere and wasted a lot of time when that time could've been spent on character development. As a kid I was like "the heck is a trade blockade?" Compare this to the OT starting off with a chase that immediately sets the tone for the rebelsvs. Empire conflict. I feel the same about how clones were explained in AOTC. We know they're supposed to explain the Empire's use of stormtroopers and Boba Fett, but it ultimately went nowhere for me (even telling me that Clone Wars show is a must watch is a pretty big flaw given that the important plot points should be part of the movie). The less I talk about midichlorians, the better.
Most egregious of all was how the Jedi were written. The plot required them to basically act like idiots in the guise of hubris without actually showing why the Jedi had so much hubris to begin with. It's stuff like this, that I cannot really forgive, nor even give some credit to the PT for trying something new.