I think it's easy to come to a false conclusion through studies like this.
Unlike BACK I click an RSS icon once and subscribe in another application—and only if I already like the site/news/feed. So for the users like me that just click the button once and awhile to subscribe to a feed in another piece of software, like Vienna or Mail, we appear as a false low.
I use Chrome, so that doesn't help Firefox in my case. But Chrome doesn't show RSS links either. I wish they still offered the option.
The Chrome extension is sort of broken - if I click the address-bar RSS icon, it opens the feed in a nice stylesheet, but I can't see the URL. This is a problem for sites that put their feeds in meta tags, but don't have an RSS link on their front page - I end up having to view source to copy out the RSS link.
I'm your average HN reader and so, I think, somewhat above average in technical matters and the few times I tried using RSS in Firefox it felt awkward and I wasn't quite sure whether I was doing something wrong.
The last couple of years I mostly read RSS on my iPad / iPhone or using Google Reader (which is okay'ish).
You are really using that awkward mobile interface of Google Reader? Why wouldn't you use an app like Reeder that is synced with your Google Reader account and has all your RSS needs covered.
For me following my Google Reader subscriptions via Reeder is a daily habit. I guess I use it more often than Safari on my iPad.
That said I would absolutely miss RSS if it was gone.
Shame that they messed up the Google Reader UI when they rolled out G+. Before that, consuming RSS was part of my morning routine. Now, the crappy web UI combined with extremely slow Android app have pushed me over to Pulse (ttp://www.pulse.me/), which is also RSS but with a much more limited collection of feeds to follow.
I read blogs and aggregators only through RSS, and I've never once used the built-in RSS featurs of Firefox. Firefox's implementation is awful - I use Thunderbird and read feeds via the same interface as my email.
