I suspect your all right to one degree or another. If all the production components, scripts, actors, camera, ect. is top notch then is easy to make a good film. If one has weak spots here and there then the others can make up for it.
I also suspect that if you don't have a good script to start with then the others don't have anything to work with or the means to make up for it.
Weaknesses can be hidden if there are enough strengths to fill in the void.