I think he means that the story on paper - the synopsis at least - should have been a 8/10 but the way they did it made it a 3/10, which I totally agree with.
I agree and think there should've been an 8/10 story but even a synopsis of what we actually got on paper was well off the mark.
1.
During an attempt to end an inexplicable trade dispute and ineffective blockade of a planet which seemed to cause no impact to either the indigenous racial stereotype frog rabbits or humans anyway, a couple of Jedis and a disguised queen end up acquiring an extraordinarily force sensitive slave child through an impenetrably complex bet with a racial stereotype flying elephant shrew. The two Jedi fight a Sith on their own because the rest of the Jedi appear not to care and one of them dies. The surviving Jedi, Renton, then begins to train said child as a Jedi, at the blessing of the Jedi council, who had spent the entire rest of the film pointing out training him now was likely a very bad idea, especially with another Sith Lord known to be kicking about.
2.
Increasingly transparently evil Sith Lord plots to overthrow galactic democracy using the most racist frog rabbit he could find, whilst Renton finds a secret army and our young force sensitive child is now wandering around in ominous black being an embarrassing teenager, going on murderous rampages and "romancing" our queen through the medium of conversation about minerals. She, naturally, succumbs to this geology obsessed psychopath's seduction. The Jedi continue to not be bothered particularly about a Sith Lord kicking about.
Oh, and someone's trying to kill the queen for some reason. But they sort of forget about that in all the thrilling excitement.
3.
In a shocking twist, our young Jedi turns to the dark side suddenly, despite two and half films running time to set his descent up properly, because the obviously evil disguised Sith Lord, who now cackles and actually talks about his extensive Sith knowledge, makes some very on the nose vague promises regarding his fears that his queen girlfriend might die in childbirth.
Our now bad Jedi goes on an utter atrocity spree and, meanwhile, almost all the Jedi get killed by soldiers because they now appear to no longer be able to see the future. Democracy collapses or something.
Good Jedi fights bad Jedi. Bad Jedi loses and shouts "Noooooo"! as he realises his queen girlfriend did in fact die in childbirth after all.
It's not great stuff.