I question the "what the public wants" part of the equation. I personally have not seen this demand for hybrids and I do not live under a rock (well, not all the time). Now when I say hybrid, I am referring to hybridization between two different species, like the OP proposed thayerii X California king. I have little doubt that lots of careless intergrades between different geographic races (like getula X floridana or califoniae X nigrita ) are sold to pet stores, etc. But the demand for Pueblan milksnake X cornsnakes or thayerii X Cali king seems pretty low. Just enough to be chump change.

Actually, I do not really care too much what the public wants. I know what I want and I know who I would go to get it. Guys that have outstanding reputation and a long history in the hobby. Coincidentally, these are frequently the locale guys.