* Not to mention, even if folks knew what RSS was, they don't necessarily want to host their own blog.
The application can obfuscate the underlying technology. You don't need to know what RSS is to use it every day and love it, just as you don't need to know about DNS, TCP/IP, or most other internet technologies to enjoy the web.
I'm still not sure what your point is - you said Twitter is trying to "be" RSS, but that's just the format, not the application. Twitter is not trying to aggregate content from elsewhere, either.
Maybe not directly, but they sure make it easy for third party sites to have "Share this article via Twitter" buttons.
Twitter can track you across third-party sites using its widgets, and it also knows your subscribing/reading behavior.
A decentralized system could be self-hosted and only pull in data through RSS, keeping you as anonymous as the IP address that you use. You'd only give up anonymity by replying to posts.
aka FriendFeed/Google Buzz. Neither of which were at all successful or exist anymore.
The problem is that there is no incentive to use them as platforms. People just output their other primary sources through them, and then engage on their primary platform.
That makes them horrible for users (who write comments and never hear back).
So Twitter wants to be RSS with better discovery. If there were discovery and UX for blogs like there is for podcasts (Pocketcasts, Overcast, etc.), then Twitter wouldn't even have a leg up on RSS at all.
I've often dreamed of a decentralized "Twitter" that allows you to subscribe to any Twitter, Facebook, or blogging feed and makes them all equal, first-class citizens (including the ability to reply/retweet/etc.)