We have to remember that casinos are private business whose aim is to make profit. They get hold of activities around to be creative. They have gone into politics where they make options for voting through bet. Although, it is already known that Christian and Muslim religion don't encourage gambling but casinos also know that some of the faithfuls also gamble. It is a two edge sword.
Christmas and the Easter celebrations are symbolic for the birth and death of Christ, the Casino's know this, and are also aware that gambling is a sin in the religion of Christians, but they still do not fail to bring up Christmas and Easter events. Are you saying that Casino's are religion sensitive?
Bible did not talk about gambling. Although the love of money is the root of evil is in the Bible but nowhere in the Bible that talks about gambling specifically.
Pastors, other men and women of God can against gambling and speak against it but Bible did not mention gambling in any chapter or verse.
Well what looks like such in the bible I remember the incident of where it was recorded that Jesus Christ scattered some people in the synagogue, those preachers and teachers where found selling domestic animals, exchanging monies and doing money doubling.