They'll learn to be pricks, no thanks. I can see teaching with Minecraft in only a few topics but not much really anything else. Maybe economics and geography.
My 3 year old plays occasionally, he usually joins random servers and tries to get into people's houses to get tools and clothes haha we have to hide our server number from his or he takes our tames for a run
actually a tribe of 300 little kids would rekt anybodys ass just because they will play alot so grind a lot so will get big they just wont be efficient