When you think about it, did Disqus kill blog commenting? I stopped commenting on other sites because of Disqus. Having to register for their service and even then most of the time I would have to login with it only to have it not find my account. Far too much trouble when something like Twitter was so much simpler. Now I just leave a note on Twitter, with a link referring to whatever I wanted to comment on. Much easier, less stress, and it works.
By the way, Disqus is now spamming you but you can pay for it to stop. Or just stop using Disqus. People might start commenting on your site again, or not. I think the days of leaving comments on blogs are gone. Too much hassle to deal with software, like Disqus