Exactly, if you've got a +% D win rate.. why NOT reward that in arena events? Or at least give some small amount of love to at least *trying* to get D wins.
And... really.. above 50... 13-15IC per win is better than allowing others plow through to 400+ wins. At least, that's how I see it. Why should I get 10IC per win when I can get 13 or 15?? I do the weak D for a day or so at the beginning.. but beyond that.. meh. It's not common enough once you climb rankings. Lots of new names in the top 100 just due to shear SOW refills.