Whirling Slash Actively Different based on Input

Why when i am playing as Keyboard and mouse and hold whirling slash do i have to keep my mouse within an inch from my character?
If i play WASD i can have my mouse on the edge of the screen and zip around.
Why if i put on attack without moving does this ability literally stop moving? (the only ability with base movement that i even think does this)
Why am i being punished for playing Keyboard and Mouse which is literally the baseline of path of exile gameplay?