My underlying point is that if physical media continues to be relevant, then so will Netflix. Everything you said is correct except for discounting their physical distribution centers. They probably have some very real and significant advantages in physical distrubtion.
I've only seen one or two blu-ray videos myself and the difference is pretty incredible. Is it necessary? Probably not. However, I do think our eye's develop a taste for clarity. The example I offer is looking at a computer monitor from the early 90s and wondering how people ever starred into these things. I think blu-ray disc capacity is 25-50 gigabytes. That's going to be a pretty hefty download for years to come. Anyway, there's definitely a place for streaming and instant gratification, but perhaps physical distribution has legs.