Here I should note that any bans on gambling completely and finally by some laws written by government officials of these countries will not work simply because people always have such a need as to gamble. This is one of the pillars of social relations and banning it is like banning all people from breathing or drinking water. Nothing good will come out of such a ban. And governments should take this into account and simply adjust their policies so that gambling would be in a civilized form. Tax policy and counteracting possible fraud on the part of casinos - this is the optimal solution in regulating this issue.
From what caused this discussion, although I've not believed what people said about politicians gambling after a state meeting, rumours and unfounded claims fly virally. If at all it happened, it was after a state meeting, not during it, so the program has been declared closed, for this, they have their free will on what to do when they are not on an official assignment anymore. This buttresses what you said as well, laws can't just be enacted to deprive people of their free will and social engagements regardless of their status.