I've heard this a ton of times, but I really can't grasp it. I've used RSS readers before, switched to Google Reader because it was better and didn't have a problem adjusting to another one after it went down.

But I've experienced this with other things, like for example I've been using Thunderbird since not long after Firefox was still called Phoenix and haven't manage to find anything close to a replacement, so maybe I shouldn't even speak up. :)