Is there a reliable way to create RSS feeds for sites that don't have them? That would be really great...

It wasn't in anyway special or unique. Though, it was a good app and it took competitors several months to years to reach a similar level. But Google Reader dominated the market back then, and them closing it was a kind of signal. It was around that time that other rss-related services went into decline, while competing solutions like social networks and reddit were on their hype-train to popularity.

So it's kinda natural that people saw the shutdown of Google Reader as a death-flag for Newsfeeds as a whole. And they are not so wrong on this. The decline continued since then and so far there is nothing in sight to reverse it and start a new hype.