Don't forget about removing native RSS support from their browser. Combined with the knock on effects of other browsers removing support "because Google did it" or "because Google Reader is the de-facto RSS reader" hurt RSS even more.
For sites that offer it, sure. I use it frequently with podcasts too.
But the number of sites, and the easy availability of readers for it (it was built into all of the major browsers at one point), have both decreased dramatically since the early naughts. If 10% of sites offer RSS feeds, I'd personally be quite surprised.
