My wife told me the other day that the creators of Minecraft was actually the same people that created some form of gambling and that this is basically preparing the children for some form of gambling (I can't remember the whole story). It was a topic on a Christian radio station. Have you heard anything like that before? I could not find anything wrong with the game when I looked at it.
In case the question was serious: I mean, when starting to 'learn' programming one of the first 'games' you learn to make is 21/blackjack. So in that respect I guess minecraft could be very loosely based on 'gambling' as all proper games use randomization and chance somewhere in the math. Otherwise, give this game to an 8 year old and he won't get addicted to gambling because he's too busy being addicted to the game. One of the things my friends complain about the game as they've grown past it is that there's nothing to do. The reality is you can do just about everything; they just want structure and someone to point them in the right direction. The game can be a great exercise in creativeness, autonomy, project management, setting and meeting goals, and depending on the mods, an introduction to electronic circuits and logic gates and a number of other STEM related concepts.