I think in this case it is still a method of portion control and assuring the customer that they are receiving a full serving/glass of wine. In these new glasses, a 4-5 oz. pour barely comes up to the curve of the bowl of the glass. It looks VERY small. While the breathing of the wine is true, and the half glass (or even less in a red wine glass) is also, half a glass in a Riedel style glass could be 12 oz. of wine!!