Turning the Jedi into a big stupid lazy church is only the start of the failures of imagination in the prequels. Don't get me wrong, the theme of a democratic society ruining itself into a dictatorship is certainly relevant, but the Star Wars treatment of it didn't give anyone the conceptual tools to do anything about it.
I disagree. The Jedi being a "big stupid lazy church" I think meshes well with the overarching plot of the fall of a decadent Republic that had rotted from stagnation and corruption, able to be overthrown--not from an external threat, but from within. It fits well with Anakin's frustration with the Jedi and the appeal of a New Order, built clean and fresh from the ground up, swept clear of the old ways.
Not only that but what we do see of the inner workings of the Order--their abduction and brainwashing of Force-sensitive youth, closing them off from emotion--expertly set up not only Anakin's downfall, due to his inability to let go of his attachments... but his redemption as well. Luke was able to redeem Anakin through familial and emotional connections, which would have been *impossible* for any of the old Jedi.
I detest TPM, and the entire prequel trilogy suffers from awful writing and direction, but the ideas
and worldbuilding are rock solid. The responsibility falls squarely on Lucas' shoulders for both. He would have been much better served with an editorial staff to push back against, as he did with the OT, instead of a team of yes-men (talented as they are.)
The sequels are refreshing because it flipped the coin. Excellent direction, acting, and tactility; at a cost of worldbuilding, logical progression, character development,
and thematic coherence (and as of TLJ, basic filmmaking). We appreciate having what Lucas got wrong, but now we miss what Lucas got right... what we took for granted.