It certainly makes the over all thing more reliable
At least as it has played at our table, the pull is most of the point of it - that's how you achieve lockdown.Rolling the attacks still marks them, so the fighter's still doing his thing, even if the pull doesn't work (and it might not work for other reasons, like not having a square to pull them into).
So having the autopull become an attack vs Will is doubly bad: (1) it undermines the function of the power (at least as I've experienced it); (2) it is a concession to the view that martial PCs can never have auto-success abilities while casters can.