My former newspaper's former comment system was (loosely) tied to your actual newspaper subscription - it's possible that's the case here as well.
As an aside - the reason the Tacoma News Tribune is my "former" newspaper is actually slightly related to this topic. They also had a perceived issue with online commenters behaving badly. Their solution was to move to a comment system that requires Facebook authentication. At that point I'd been a print subscriber for over 20 years, but I ended my subscription. Ahead of the switchover, I had an email exchange with Karen Petersen, who runs the paper. I told her companies like Facebook were exactly what newspapers needed to keep an eye on, and that there were plenty of other discussion board products (e.g. Disqus) that would accomplish what she felt needed to be done. It was pretty obvious she was just parroting back some sales pitch someone had given her when she replied ("we need to require real names to prevent abuse, and Facebook will accomplish that") - it wasn't surprising, but it was disappointing.
It was probably for the best anyway. They were already becoming less and less of a real newspaper, filling more and more space with entertainment twaddle, and, even when they did cover actual news, the stories kept getting shorter and were mostly devoid of real content. It was pretty obvious they weren't thinking about what their remaining subscribers wanted - they were following some consultant's advice about "attracting the kids" or whatnot.