Except that it's still only a soft denial, not a hard one. The choice is there for the opponent, they can either choose to make use of their extra card draws or not. It's still only a single turn per use, the opponent still has an opportunity to play any cards drawn (unless locked out somehow, in which case they face other problems anyway), and they still have the choice of drawing cards past one or not. And that's all coupled with the fact that the caster is using up a deck spot for semi-denial, meaning that it's going to require setup to get maximum use out of it.