I still haven't seen anyone contradict me in that 9 of the 12 bands could fit on any given year. Can the naysayers please address this?
You're right. The problem is that those 3 bands make up 3.5 hours of the 12.5 hours of music, and personally, despite their repeat status, I count Therion as one of the oddballs, making 5 out of 12.5 hours. Plus, even though I do love some of the bands, others, despite being part of the normal formula, just aren't my bag, so for me, there just isn't much more music here than I would get at a local show. By placing oddballs into 3 of the 4 top slots, the rest of the lineup had to be nearly perfect to attract me to it, and I'm sure I'm not alone.
Perhaps I could just change the fest name to "ProgPower USA Repeat?" Or "Prog(notreally)Power USA? Or ProgPower(butonlyifyoualreadyknowthem) USA?
I think you're falling into a trap here. Has any other major festival in the world felt the need to change? Sure, they change with the trends, but PP isn't changing with the trend, it's moving against the trend. The big power bands are growing more and more popular with each new release. Yes, due to the fact it's the same power bands, PP will feature more repeats, but who is popular governs how every festival books. Avantasia headlined Wacken only a couple of years ago, and it will headline Wacken again simply because they are one of the biggest bands available to Wacken. In the 7-day sellout years, PP too booked the biggest bands, even if they were repeats. The focus has shifted since then to keeping the festival roster fresh as possible, but if new bands aren't stepping up, what can you do? Start booking bands in other metal genres? I don't think that's going to work.
The brand name is ProgPower. If that means the same bands that sell the units and tickets come every year, that's not your fault, that's the industry's fault. But if you think the headliners need to branch out into thrash, doom, and whatever the hell Therion and Arcturus are, might I suggest Atlanta Metal Festival?
I highly doubt many people went just for Kamelot and Hammerfall. Considering Hammerfall toured previously in the year and Kamelot was going to tour after Progpower, I don't think anyone really made it out because they were such great headliners.
I can only go by my tastes, and the empirical evidence: the big power bands at the top sell out. Every time. Without fail. Other headliners struggle. Which tells me a) the casual fans that are on the fence every year love the power bands and b) casual fans judge the fest mainly by the headliners. And bonus, c) of the 7 PPs that sold out, 3 had a repeat at the headline slot. Of the 4 that did not, one had a repeat band in the headline slot. I'm not saying that repeats are what the fans are looking for, just that I think you all overestimate the attraction of exclusivity and new bands and also overestimate the negative reaction to a repeat band. Especially when the repeat band is supporting a buzzworthy new release.