Eh, most movies get at least 3 years from green-light.
If the script turns out better, Abrams should be praised for rewriting it, and delaying the movie 6 months.
Sure as Hell, if he had gone with the script and it made the movie suck, Abrams would be BBQ'ed for not taking the time to fix the script, "As The Director, it's HIS Job
". (How many times have "WE" trashed Directors for not re-doing a script?)
We don't know for sure that most any credible Director wouldn't have wanted to alter the script. (And I think most "In-Demand" Directors would want their own stamp/angle on a script in some way, even if it's already Good)