There is a simple reason why this is (for now) a utopia:Reliability.
While I can perfectly understand watching even lower than optimal quality, the fact remains that In order to watch your favorite DVD/Blue-ray or similar you need only electricity.
To stream you need electricity and Internet.
Last I checked, Internet providers do not pay you back your money if they stop providing service for a "short time" (how much that is depends on your provider).
Even worse, the prices and rules of anything like that (online services) can be changed by your provider anytime they want leaving you with a simple decision: "If you dont like it, dont pay for it and you wont get it ".
With physical copy, that dosent happen.
Also, lending a physical copy is something possible and rather normal (well, for now at least). With streaming we dont know how it will look later on.
Finally, considering how badly companies behave when they "can", trusting them is plainly dumb (naive is cutting it short in my book).