Yep, that's because of Fitts’ Law: the time we need to click a button is a function of the distance between the pointer and the button, divided by the area of t

Yep, that's because of Fitts’ Law: the time we need to click a button is a function of the distance between the pointer and the button, divided by the area of the button. When the button is in a corner the size is virtually infinite (we can move the mouse all we want in one direction and we'd still be over the button)