Well I don't take much stock in those sorts of theories. They very well may be true though. It doesn't actually take anything away from Asatru. All it means is the heathen gods were at least as real as the Christ.
After all, the boundary between god and hero is a slim one. A hero is a great man whose tomb is still kept sacred. The gods were those so ancient that their graves are lost to the ages and so great their names still live on without them. Isn't that what's Asatru is about? Honoring the memory of those ancient dead?
I don't think ritual and ceremony is bad. We perform them for mundane things. We celebrate the holidays we no longer hold sacred. We feast to celebrate events. We celebrate the anniversaries of our kin's birth and bestow them with gifts and wish them longevity. We celebrate marriages between houses and we drink to their health, to their wealth, their happiness, and to their fertility. Hell we like getting drunk for it's own sake.
We don't shave during playoff events to preserve the luck in the locks of hair, we keep four leaved clovers and horseshoes and we're afraid to wash the luck off our garments. We know it's nonsense, but it's still something we do. Just to be sure.