I stated a fact and explained why it's a fact. It's a fact that the reason games include crafting is because it gives players a chance to make things that are then usable within that game. It's opinion that doing so is rewarding and enjoyable (though apparently an opinion that's widely enough held for it to have been worth incorporating a crafting system into just about every MMO I know of and quite a few single player games as well). It's something that some players care about and others don't, certainly, but crafting exists because of the ones who do.
