Among other things, Bosch manufactures washing machines, dishwashers, and microwave ovens — why do their interfaces differ? They’re all appliances made by the same brand! Because they have different purposes and you use them in different ways.
Actually, as an owner of both a washer/dryer and a dishwasher from the Bosch “Serie 6” range, this makes the opposite point intended. The interfaces are bafflingly, irritatingly different for no good reason, and would really have benefited from some central alignment on UX patterns.