I've held this opinion about game designers for a couple of decades now. Very few games even try to get anything right and the designers of games like D&D have never succeeded. The internet only means game designers are even more stupid because in a few minutes, even 14 years ago, you could do...
Game designers are morons at best. http://www.thebarrelmill.com/barrels for new barrels. and http://www.distillerytrail.com/blog/understanding-oak-barrel-maturation-part-1-know-your-casks/ for lots more sizes and information.