I think the point is, FFXIV has bland -REALISTIC- areas. The whole argument for the areas being so huge and all looking the same is that they tried to make the game feel realistic. As such they shouldn't have ridiculous mobs.
I believe they originally had a really good idea (which was to make the world interactive in that mobs attacked each other, etc) But they seem to have scrapped that now.
Birds are pretty well the only unrealistic mobs in the game. So it makes sense to redesign them or scrap them.