You gone a little to far with saying that fiat based casinos are worthless. You can find many informations about how big gambling industry is, I will not share any numbers because I come across different informations but generally fiat based casinos worth much more then online gambling industry. Online gambling is growing, but its still small for fiat. I will tell you just to take a look on Macao and Las Vegas and how much money is spent there for gambling, and this are just two cities in two countries.
Online gambling is the future, and bitcoin gambling will be huge part of it. Gambling market is very big and I think time needs to pass for us to see bitcoin on top!