My take on it:
It's become a marketing word that has gone beyond California. So you're going to see a lot of misuse of the word "kush" or "og". If you go to any of the other big grow sites and search for the word "og kush" and sort by post date, you can see when the term started proliferating in the market.
You'll have the purists and breeders, especially in CA, which will never call anything kush or og unless it has the genetics to back it up.
But, for your average mcdonald's consumer, they won't know or won't even care the origins of "kush" or the genetics of the strain they're growing. Just check any of the MMJ trade magazines with dispensary menus. A lot of them "carry" strains that i've never even heard of.
As for growers, it only makes sense for us to grow something that is in high demand. Most kush-genetic strains grow reasonably well indoors with little-to-no training involved. But again, like what happened in the 70's/80's, you see more growers leaning toward indica-phenotypes, which result in faster growth cycles and shorter plants.
I'm sure a good haze-genetic could be a good seller in the market with it's strong sativa effects, however, when you have some sativa strains growing 5-6 feet tall from 1 foot tall when you flip to 12/12, along with 10+ week flowering types, economically and practically make it a hard venture to undertake.
My 2 coppers.