If there was ever a show that would benefit from a OnDemand/Netflix type rating, this is it. According to the article I read, the finale was only watched by about 74,000 people (though, by comparison, I think Gravity did WAY WAY WAY less than that). Problem is, I don't think many people, as evidenced by that number, watched this when it aired. Hell, I usually watched it OnDemand, because the episodes went up DAYS before the 'initial' airing date. Regardless, Rob Thomas (who isn't the one that'll cut you) seemed to imply that the real cancellation reason was that Starz hired a new president, the guy who was at HBO when HBO initially passed on Party Down, and that a third season likely would've happened if the old president was still around. One of my other quibbles is, really, it was a half-hour comedy on Friday night on a channel that isn't known for original programming. The sheer fact that it even got a second season is a miracle.
It's a shame, certainly, but it ended on a strong note, so I can live with it. Plus, it avoids the issues of Ryan Hansen and Adam Scott having other jobs.
Awesome show.