WAIT, unless your comment was sarcastic, in that case :FacePalm: lol!
No, I actually do like Greagoir
He has interesting dynamics, opposite of what we usually see. If you check out the first Dragon Age comic, Greagoir is terrible to mages in the beginning! But he gets softer as years go by, and in DA:O it looks like they are friends with Irving. I mean, they still plot against each other during the origin (actually, Irving does that, Greagoir doesn't), but after the Broken Circle Greagoir is really happy to see Irving alive, and accepts his word as a proof that they are not blood mages. And if you annul the Circle, Greagoir gets depressed and quits. I think he used to be a very ardent templar, but after living near mages for years, he realized that they are people too. I don't defend him, but I like that he's not a blind zealot.
Greagoir lets the Warden inside the Tower not because he doesn't want to do anything himself, but because the Warden insists that they can't wait, and Greagoir must wait for the Rite of Annulment. He can't just walk in and murder everyone (like Meredith does). And he doesn't have enough men for that.
Greagoir was also the only one who tried to help Cullen. Sure, he told him to shut up first, but they all were very stressed after the abomination business. And later Greagoir sends Cullen to a quiet village to recover, and that apparently helps 