I know people like video streaming, but I never understood why Netflix really refocused their business to streaming. They basically created a near-monopoly on video rentals, destroying all of the DVD rental shops across the country. Yes various forms of streaming services are going to compete with that, but there was never any way for Netflix to obtain and maintain a monopoly on video streaming. It's something that really any company can do, and they're constantly going to be fighting over the rights to stream various titles. It's why Netflix streaming doesn't have everything, and why titles disappear regularly.
As long as there are DVDs, the first sale doctrine means that Netflix can have the greatest video library in the world and nobody is likely to try to compete with that directly.
Maybe the DVD-by-mail model won't last forever, and probably getting into streaming was a smart move. But their streaming library will never be as awesome as their DVD library potentially can be.