While it's probably true that geeks make up most RSS users, that doesn't mean either that it should be this way, or that it will remain this way, or that there is some obvious and immutable reason that it must be this way.
In fact, of course, using an RSS feed is a very simple concept, which turns out to be extraordinarily useful to normal, non-geekly folks who just want to read a lot without being pestered by all the normal encumbrances of the web.
While I agree that feeds are a simple concept, the vast majority doesn't care. Feeds have been available since the early 00s and its adoption hasn't grown outside the geek circles. People just don't like to be bothered with the simplest complexity.
I bet less than 80% of ordinary people even use bookmarks, being way simpler than feeds in concept.
In fact, of course, using an RSS feed is a very simple concept, which turns out to be extraordinarily useful to normal, non-geekly folks who just want to read a lot without being pestered by all the normal encumbrances of the web.
So, your argument strikes me as weak.