The thought of having to rip out the RSS infrastructure now in place is unpleasant to me, and the forces aligned with (Not)Atom have done a poor job of engaging the ordinary RSS-using public (people like me).
What RSS infrastructure? The RSS "infrastructure" is XML. There's no "ripping out" of anything.
And even after seeing the power of XML over the past 4 years, I still wanted an RSS framework at one point. Fortunately, Chris pointed out how foolish that was. So I'll say it again - it's all about XML, stupid.