For me, the value of the blacksmith is in making tools, weapons and other items that make other workers more efficient. If you really want your blacksmith to earn money directly, you can have them make steel. I don't think it would be a good idea to rebalance the game so that crafted items make a profit, since it would be really easy to wreck the balance of the game.
There's also nothing a skilled craftsman can make that an unskilled craftsman couldn't. It's not even any more difficult for an unskilled craftsman to make a valuable item than a skilled one, they just generate generic "work units" slower.
Food is also an interesting subject. Obviously you've only got 4 types: vegetables and grains which are the cheaper options, and meat and fish which are 50% more expensive. Vegetables and meat are the "rarest," which means there's "only" ~50 units of each at the neighboring town, bread is the most plentiful with ~100 units of grain and ~50 units of bread, and fish would be in the same boat as meat and veg except you have a resource node unlocked at the beginning of the game. Therefore, I think it makes sense that making meat soup is the most profitable use of your chef's time, while bread is the least.