The problem is that the cost of the so called descriptive domains such as “hosting.com”, “onlinecasino.com”, etc. are such that you could take the same money and be able to advertise for the #1 position keywords for a considerable amount of time. These domains can run 6 figures and up. And there are so few of these domains available. I guess my point is why worry about something most will never have?
And I don’t know if it is unique to the online gambling sites but I’ve also not run into problems with sites linking with me using keywords instead of my domain name.