I agree - I think it's clear no actor was receiving good direction. Hell, look at Natalie Portman's wooden ass performance in the prequels and her amazing performance in Black Swan. Doesn't take a genius to see there's a ton of talent that was just wasted there.
Or Samuel L. Jackson. A guy that's consistently portrayed as being 'larger than life' in either his serious, comedic, or downright zany roles... is somehow turned into cardboard for the only time in his acting career, something apparently only the talents of Lucas and a green-screen film studio could pull off.
Just look at the performances in Avatar, compare Saldana's performance in Avatar to her performance in Star Trek... really, "green screen film studio" has ABSOLUTELY NOTHING to do with it.
Blame it on Lucas if you want, but for crying out loud, please stop that green screen/CGI bitching, people, please!