It's flawed for another reason. Humans don't live in trees!
A chimp has to be able to throw itself around thirty foot up in the trees without falling to its death. As well as great hand-eye coordination it also has to be able make very rapid mental maps of where all the branches are. One glance probably fixes in its mind the exact location on every obstacle and grasp point so that it can move swiftly and seamlessly through the treetops.
It's not general intelligence, it's a life skill. The test, whilst very cool, is about as relevant as a man racing a Cheetah. Gets some nerd with a lab coat his five minutes though so hey ;0)