Bread bakers seem to be very happy.

That's funny that you noticed a difference. It reminds me of some young culinary students comparing the students training to be chefs vs. the students they met in the pastry chef courses. Both of the students agreed that the students planning to be savory chefs were in general  wild, liked loud environments and were more disorganized compared to the students  studying pastry whom they deemed to be much more quiet and organized in their method of working. I have no idea if the difference is true I am just reporting what I read. Are bread bakers happier than cake makers? I don't see why they would be. Both are making wondering things by hand Someone else who works with both should chime in-- it could be an interesting discussion. I know I feel happy after baking bread but am just as happy when my cakes turn out well. Tonight I used a new recipe from England for a whole orange cake. This involved simmering a whole orange then pureeing it skin and all. It did not turn out as tasty as I thought it would, it was too bitter and not light enough despite cake flour and the recipe had an omission error in it that I only discovered as I was doing it and had to guess at something, so I was not a happy camper after that less than great cake which was to be our Mardi Gras delicacy.