For the textfield you mean? In that case it’s because then people are going to be lazy and not make a ‘hit’ layer. Also it would only work in the area of the textfield, and that no good. Third thin: if we were to pass an element when clicked, it is more suitable to have the event.target point at the whole MC instead of just the textfield.
was this what you were looking for?

But now I realize what you mean, and here is my answer:
Because we’re going to animate our button in the next part, and we can’t do that with a simple button. I can see the title is misleading, I will change that now :)