I wonder why nearly every self-hosted alternative RSS-reader here is a web-app; isn't using a desktop-application desirable? Like Firefox, Thunderbird, Liferea[1], Akregator[2], and probably lots of OS X applications?
So much of what you're reading in RSS-reader is web content, naturally you'd want to click through things in your existing browsing experience. At least that's how I view it. I'd like to use a desktop-app but find myself never opening running it and instead jumping to feedly/google-reader etc.
I'd really like to have a desktop-app w/o web service that sync'ed to my phone which I also like to read rss on.
My solution was (and still is) using Pocket[1] to read. I absolutely hate reading on laptop/desktop. I instead check out the feeds every so often using a desktop reader (elfeed nowadays, but seeking for sth. else as I'm no longer using Emacs), and save those I want to read to Pocket. This way I do not need an app that syncs my feeds on each device I have, but rather only Pocket on each of them.
That's why I read RSS via IMAP. All of my devices have an IMAP client on them. I have a script which downloads RSS feeds and sends an email to me for each item, which is then filtered into a News folder via a Sieve filter. I spend half my time in my email clients anyway so I may as well get my RSS fix in the same place.
Because people want to sync their feeds and their current reading state across multiple devices (desktop, laptop, tablet, phone...).
I also read my feeds somewhat sporadically: Since RSS usually only contains the last ~10 entries I would need to open my feed reader at least once a week to avoid missing an article.
I don't think I'm an RSS power user since I mostly use it for comics (~30), some techblogs and a couple of tumblr feeds.
I'm currently using bazqux[1] since it is fast and has a no-frills interface.
[1] http://lzone.de/liferea/
[2] http://www.kde.org/applications/internet/akregator/