It's not just Dunlops, Avon Roadrunners are like that too. I guess I'm just used to it. I always figured it had to do with moving water out towards the edge and away from the tire under the conditions where it's most important. On the front tire, it's most important to have good stopping traction, since that's where you get most of your stopping power. On the rear tire, it's most important to get good acceleration traction.
With the "V" shaped treads aimed the way you'd think they look best, they would actually be funneling water towards the middle of the tire when stopping on a wet surface.
