I realize that it is frustrating when manufacturers/vendors do things like this. But to be honest, it is business. I am sure any of your who work for a company that makes and sells stuff you understand the need to differentiate and justify a higher price tag for what you consider the higher end option. From computer systems to phones to camera gear to pretty much everything. If you want to have two tiers of pricing/product then you have delete some of the nicer features from the 2nd tier model. And we all realize that the LX is not simply an LC with AHC. I'm pretty sure that Toyota/Lexus want to hold some things back from the LC to justify the price of the LX. Its not personal, its just business.
And as for retrofitting, I'll bet it is not simple or cheap. But maybe it is worth it for those of you who need the capability? I could say that I never need or use the DCC in heavy traffic or when commuting. But I don't need to commute any more so my situation isn't relevant.