Transporters were a key device on the series, a key to the storytelling.
Knowing that warp engines have to be made in a gravity well is a pretty tiny little detail, one that would be about 8 millionth on the list for storytelling (if that high), UNLESS it was a particular story point (or thought up to deflect criticism.)
The point is that Orci made that statement because he is just trying to prove to the hardcore fans that they are putting at least a little thought into what they are putting on paper and on film. I can't criticize him for that, but I do criticize him for trying too hard to reach out to the hardcore fans by explaining the minutiae of his thought process.
He probably better off just doing what he thinks is best and shutting up about it. This episode proves that.