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.
You have a point in what you say and that is true, but even that is not mentioned the meaning of gambling. Maybe it can be found in the book, like the word Diabetes you will not find it in the Bible but you will find its definition in the Bible.
Also, to my knowledge, gambling is strictly prohibited among Muslims, I am not mistaken in this matter. Although the majority of religious groups do not think well of it.