Between Emblem design and how so many encourage being the aggressor, Chain Attack which itself encourages aggression, fliers being jerks ideally shot by archers who are notorious for having a weak EP, and thieves, I figure WTA having no effect when defending was another one of many decisions to encourage moving forward no matter what. ~~Tatakae, TATAKAE~~
Could WTA have -some- effect when defending? Maybe, but I think not Breaking was a balance decision because it disproportionately affects Swordmasters who lose a lot of power if they're incapable of doubling. Halberdiers wouldn't be affected as much, while Berserkers will laugh because they don't normally double anyways -- and then there's all the classes that exist outside the melee triangle.