It seems a costly step to have a brand new airplane visit a third-party STC installer to receive its wifi. However, I assume the great minds at AC, Boeing etc have considered this, and the lean 737 assembly process at Renton is such that installing wifi on the factory floor might slow down the build itself. I'm sure most realize that the airplane is constantly under motion as it's being assembled. Or perhaps the assembly line is off-limits to non-Boeing personnel.

As an aside, it strikes me as odd that some people claim connectivity is so important that being out of internet service for the length of time a CR9 can fly is an issue. Surely there are alternative methods of transport (or staying home and communicating online) for those times in which one must absolutely positively remain connected.