Just because someone can get a coffee plant to grow coffee in California does not mean the coffee will be any good. Coffee grows in a lot of places, really good coffee takes particular terroir to grow really well. E.g. low grown coffee generally doesn't taste very good and altitude alone isn't the answer. The combination between altitude, soil, climate(cold at night, hot in the day) makes the bean develop slowly and generates more flavour. This is not speculation, this is information that coffee agronomists understand.
So, it's totally ok for somebody to sell expensive coffee as a novelty. What is disappointing about this article is it extrapolates from a sale of 250 lbs of beans to a "Gold Mine", implying that other beans grown in California might be sold at a similar price. They won't be, because they will likely be very poor quality. With the extremely high costs of production of the coffee, it likely won't be profitable except as a novelty.