It shows what kind of director George Lucas is.
Even the actors I would call greatest of the greats are written badly. Liam Neeson approaches Qui Gon like: "Well, this sucks, Oh well gotta get paid somehow."
As said before, Natalie Portman is very good, just not as the wooden Padme.
If you look at how George directs people, he is more concerned with what the shot is gonna look like. All in all, George has great ideas, and he is good with a camera, but when it comes to actors, he aint no Scorsese.