When did Nexon add this?

That is true. The higher your "hands", it's less likely you'll fall off of a ladder/rope when hit.

Hands was added WAYYYYYYY before maker. So it probably doesn't have ANYTHING to do with it.

i don't think that's true. everyone has the same chance getting knocked off (probably 100%). my bishop has as a very high hands stat and still gets knocked off ladders every single time. now, when getting hit while actually moving up the ladder is different. since you're holding up, sometimes you can catch the ladder again right when you get knocked off, making it seem like you don't get knocked off at all.