Decaf is a drain

Starbucks says it will try to scale back the preparation of decaf coffee (although it will still make it when customers request it). This is interesting, because I've noticed how frequently coffee shops will simply not have any decaf prepared, probably because it is so rarely requested that it's just a waste to brew a whole pot and then let it get cold when nobody orders any. But what I don't understand is why they would decide not to make it in the afternoon. I find it hard to believe (though it must be the case) that demand for decaf is less in the afternoon than in the morning. I would think it would be the other way around.