Netflix on the 360 requiring Xbox Live is not an artifact. It's just a cash grab.
The 360 was the first console to offer Netflix and they had exclusivity for a while so they could do it. Once the exclusivity ended they didn't make it free because they felt no need to because lots of people continued to pay up.
Allegedly this was a reason that BBC's iPlayer took so long to arrive on the 360. The BBC's charter was somehow contrary to MSFT's insistence that iPlayer was available only to XBL Gold members, so the release of iPlayer on 360 was delayed by years.
The 360 was the first console to offer Netflix and they had exclusivity for a while so they could do it. Once the exclusivity ended they didn't make it free because they felt no need to because lots of people continued to pay up.