As Reed says, the streaming business is global, but the DVD business is US-only. Maintaining code that services functions that apply in some locales but not others will slow down Netflix's ability to innovate.
Yeah, we all love paying two bills each month, having to search for content two places, having our ratings queues forked and kept out of sync. Thanks, we're all so glad to hear that it's easier for you.
We'll make it even easier: find new customers. We're gone.
I would be interested in what you find as a good replacement because I might consider a switch if it were good enough. I just killed my cable and that was costing me ~$70/ month.