RSS was and still is great for following a few blogs that were relatively infrequently updated. If I follow Rands, DF or Marco, it works quite well. I receive timely, relevant content at a pace I can cope with and digest.
The problem with RSS is that it scales incredibly badly for large, content heavy sites. I don't really want to see everything that Gizmodo publishes. I certainly don't want to see everything that HuffPo, Buzzfeed or any of the other content mills publish. Sure, you can choose granularity - a 'US Politics' RSS feed for example, but that puts too much of the onus on me and I'll end up missing some stuff I'd like to see.
For those large content mills, Facebook actually does a quite good job of bubbling stuff up through my network that I care about. Twitter served that function for a while before it became more about noise and snark.
The death of Google Reader probably had a role in the decline of the small independent publisher (how many new sites have appeared on that scene recently?), but it's probably not to blame for the rise of BuzzFeed et al, which RSS was never really suited to handle anyway.