To be honest, cake mix is basically the things you'd have to combine to make cake batter pre measured. It's not some magic thing you can't recreate at home without just measuring a bunch of stuff out. It's flour, baking powder or soda, salt, dry milk, sugar, and oils. They have extra stuff as preservatives but that's basically it... Using it instead of measuring takes out the uncertainty and makes things more consistent. It's fine if people want to measure everything and make their own cake mix, but don't shame people who just want to save time. Also in all honesty, decorating a cake is way more work and actually requires talent, than baking the actual cake.