Okay, so even with Reader being this good, the RSS protocol was still dying because most people have moved on to other ways of consuming news. So then if RSS didn't have a reader that was this good, then it would've probably died a lot sooner, and Google Reader actually prolonged its life. Without Google Reader, RSS might have died 2 years ago.
So I don't know what's with all this "Google killed RSS". Google didn't kill RSS. Twitter, Facebook and RSS' "geekiness" that made sure it never crossed that "chasm" into mainstream usage (and what doesn't grow will probably die, as nothing is constant) are what killed RSS.
As a side note, I'm someone who consumes a lot of news every day, yet I still found a service like Reader to quickly become overwhelming, and I've barely used it occasionally. As we've seen, many of these journalists actually had thousands if not tens of thousands of unread news stories in their Reader, which I think is also why not that many people were using it. It felt overwhelming.