It's not just about the data: it's about the habits and familiarity surrounding the process of using the data.

In RSS, I've been using NetNewsWire for years, even though it's basically abandon-ware and has really fallen behind. Why do I keep using it? Because it works okay, and when I've tried to switch—most recently to DevonTHINK PRO—I've gone back to NetNewsWire.

I'd happily pay for a new version or for a better OS X desktop-only RSS app, but I'm a very small market.