I'm another user disappointed by this; there are still many parts of the world (including here in NZ) where internet data is generally capped. Blowing through your monthly cap early because a streaming site denied you the right to choose a quality that is most suitable for you, is very frustrating.
I understand the benefits of having an automatically-adjusted quality level -- for most of the world. However this is the internet, a market that reaches all corners of the globe. Taking away our ability to /choose/ how we consume media is rather unfair. Even youtube allows you to change from "auto" quality to any of your choice.