Actually im not a vietnamese person but in my own  opinion why vietnamise people love to play dice because  this is there traditional gambling of there country and a part of recreation or relaxiation to there ownself . mostly vietnamese  people is busy in agriculture like planting rice,making a hog raising livestock etc.so after there daily works they have a place to gather each everyone of them by relaxing themself,so thats the time they play a dice and after so many past several years they develope it games and turn into an online gambling.