It really did make a difference. Regardless of whether we here prefer Messiah or Rob, or enjoy both (as I do), I know of so many people who didn't go because of Messiah's absence. Even so though, Candlemass are just not that big of a draw in the U.S. in general. As already mentioned, certain places like NYC might fare better. But I mean, when Candlemass last toured the U.S. in their heyday, they played at the Avalon Nightclub, which could only hold a couple hundred people anyhow. So as much as I hate to admit it, they never really were that big of a draw.
Alot of the shows I've seen this past year at the Pearl Room haven't drawn spectacularly. I think the distance tends to deter some people, especially for those older groups like Candlemass, Possessed (another great show but not a huge draw), etc.