Instead of stopping, better to find ways or solutions in implementing rules that will benefits
both sides, battling from illegal gambling would be a tough job but negotiating and have a good open forum on this
matter may help, providing better and proper law that will address this issue is better in solving illegal gambling activities
from the government jurisdiction.
Which shows a lack of understanding about human nature, it is impossible to stop people from gambling and any kind of prohibition will just create black markets in which people are simply going to be scammed or be abused, if they instead legalize the industry not only they can obtain taxes out of it but they can also protect their players, to me this shows very clearly that it is way better to regulate a market than it is to prohibit it which is what they are trying to do.
Anything which is under prohibition attracts a lot of curiosity and the people are more drawn in to it. Ideally they should make the gambling industry legal and regulate it. Also, prohibitions don't work nowadays, when the industry is perfectly legal in neighboring countries. The Thai citizens can just travel to the neighboring nations and visit the casinos which are operating there. Now the only losers are the Thai government, who will lose out of the tax revenues from the casinos and job creation.
Thai government needs to consider every factors before making any rules that may pushed their citizen to travel away just to gamble,
imagine those possible taxes that instead the government enjoy it will be move away from their jurisdiction.