I preordered CoH 2 because... well, it's Relic. I've played Relic games since DoW 1 and they haven't disappointed me yet, my faith in them is big enough for preordering.
I pre order if I can trust the seller and in a way to show support. It's also nice to buy it ahead of time when I know that I will buy it in the future anyway. I'd rather pay ahead of time if I can. 
This. I preordered the game because I too trust that Relic will make an outstanding game.