danny_boy said:

So the trick is to take a some-one (young or old) who does not have a clue about anything star wars and expose them in episode chronology- just to see how shocking(or not) this conversion from good to bad is.

I don't think it takes a new viewer to see the flaws in the films. Lucas seems to have lost himself in the EU, falling back on telling his audience a few superficial facts about a thousand different creations, rather than showing archetypal stories of a few individuals via dramatic conflict.

In Anakin's case, no dramatic transformation takes place on screen. In TPM, he's a sweet innocent boy. By the next film, he's a spoiled brat, a completely different character, without explanation. Scenes that demonstrate transition like that are what make movies good. But they are completely lacking in the prequels. Since Anakin already starts out as a bad apple, him "turning" to the dark side is not a meaningful story. One is left to wonder what's the big deal?

The obvious solution would have been to make Anakin a strong and noble character who experienced a series of carefully constructed events that caused him to fall from grace. Apparently that kind of extremely difficult writing is far beyond Lucas's abilities and he did not want to delegate the script to a more capable scribe.