I think the coolest feature of it was its massive database of RSS feeds. I liked being able to flip through tons of categories and add them. However, it wasn't enough to keep me coming back, and that's probably why Google is discontinuing it.
I wish there was some way to export all those feeds, though.
That pretty much describes my relationship with Twitter, and almost none of my friends use Twitter. But I don't think Twitter is any less important for that; likewise, don't let your lack of interest in Reader blind you to the fact that it has high utility for others.
What surprises me most is that Microsoft, which has a severe case of Google envy hasn't created a web based RSS service of it's own. They should make an offer to buy Reader and Feedburner too, since Google seems to have little interest in supporting these products.