Because by splitting the accounts - they've removed pretty much the only piece of value that they provided over Hulu/Amazon/Redbox. There was one single place that I logged on to with my ratings, my recommendations, my queues for both streaming and DVDs.

Without that, their competitors are now almost pure drop-in replacements for their product. NetFlix had an advantage (to me) in that everything was unified. Now that they're split, that's gone - and they have to find some other way to be better than the other offerings to justify me keeping my subscription(s).