I don't disagree with you. However, I think there was something more at play here; the size of their discography.
Every year Glenn has bands who I haven't heard (or have heard, but whose music I didn't pay much attention to). Some of these bands I love, some of them I don't. For those that I love, by the time ProgPower rolls around, I know the words to half their catalog. I think when Rage was announced, people took a spin over to their web site, looked at their discography, and said, "Oh, screw this."
I think had Rage only had three discs to their credit, a lot more people would have bought those three discs, been into those three discs, and would have been there when they played live. Instead, they saw that Rage had 20 discs, said to themselves, "I'm not going to know any of the of the songs they're going to play", and chose to blow them off.
By the way, this is just my own little personaly conspiracy theory. I'm not sure if there's an ounce of truth to it.
Zod