Time.com recently wrote a list of the (10) things that still bother fans about Episode I: The Phantom Menace. Instead of reiterating their points (which are mostly valid in my opinion), I thought it better to distill them down into a single root cause. Too much venom has been spewed over this film in particular to haggle over the details (a natural consequence of fan anticipation, aggressive marketing and the media making it the most- hyped movie in motion picture history). While it's easy to citizen the thinly-veiled ethnic stereotypes, questionable science (Midi-chlorians??) or even Jar Jar Binks, the most prevailing problem with Episode I is the script itself (and its interpretation by the actors). Opening a movie with a trade dispute and following up with Senate proceedings is a sure-fire way to lose half your audience (people only have two reactions to politics, divisive or dismissive). That said, the acting chops of the people involved should have been more than enough to keep us engaged until the pod races and lightsabre duels.
Here are four respected actors, Liam Neeson, Natalie Portman, Ewan McGregor and Samuel L. Jackson, (whose resumes include Golden Globe nominations and an Oscar win), that could not get us to accept the material and just enjoy the movie for what it is. Although Harrison Ford once quipped that Lucas has no patience for the process of acting, it's hard to blame his direction for their dry, listless performances. If Richie Cunningham and Shirley Feeny could make it work in American Graffiti (TV veterans Ron Howard and Cindy Williams), it's reasonable to assume they could (we're talking about Oskar Schindler and Jules Winnfield here!). George Lucas relies on his actors to bring gravity and sincerity to what are basically comic/pulp stories. This is probably why he spends so much time casting his movies; a lively ensemble can strengthen even the weakest script. Whatever chemistry Lucas saw in the casting room is obviously missing in the final product, however, and I point a firm finger at the cast. They took the easy road and chose not to challenge George with new ideas. Peter Jackson and the folks at Weta took an 'all-hands' approach to the Lord of the Rings material; Tolkien's stories are even more hallowed and sacred. The script for those movies was rewritten daily to take advantage of good ideas, and the enthusiasm of the cast shows on-screen.
It looks to me like the actors were uncomfortable with a large part of the movie being shot green-screen on a sound stage, and that anxiety is prevalent in their performances, (particular Neeson's). Although a common practice today, the films of the late 90s still benefited from elaborate set design and props. Even Episode I has a fair amount of physical sets, and the actors seem more genuine in the scenes where they interact in them. It's the digital effects that put the actors off, giving their performances that 'wooden' quality. I think it's high time we place the blame where it's deserved. While George Lucas is certainly not without fault (he wrote the script after all), the film could have been that much better if the cast took a vested interest in the creative process. These films are not awful, they just don’t have the emotional weight to carry a questionable script.