They probably got paid a huge amount to promote gambling, but they didn’t think about the consequences. Just imagine losing an account with millions of followers because you promoted an illegal casino. That’s years of hard work gone in an instant, all because of greed.
One thing about illegal casinos is that they are always ready to pay a huge amount for their casino to be promoted. Because of the fat money that has been set aside for promotion, most people don't even take the time to learn more about the casino; they are only interested in promoting the casino to get paid.
If you are working for a casino that is not reliable in one way or another, there are consequences. That is why it is important to make inquiries to know more about the casino one is promoting, because promoting an illegal casino means you are part of the casino as a team, whose interest is to take the casino to another level.