Not to mention that almost all those participants are fresh blood, where the majority is extremely active on the forums. And not just that, a lot of the 1% merited users are also participants https://bitcointalk.org/index.php?action=merit;stats=topusers
All those factors easily add up to make the campaign participants one of the most merited users on the forum. If you took out DarkStar_, Loyce, a few other big names, and maybe reduced the number to double the average number of every other campaign, it'd look slightly more "normal".
Like I said I don't want to undermine DarkStar or his ability to pick great users, because that's still true, but I had to say this.
If the campaign did not have users that earned a lot of merit, then it would not be a campaign that earns a high amount of merit.
It just feels like you're making a tautological comparison. Sure, subtracting the merit elements of the campaign would make the campaign hold less merit. That's just by definition.