Humans, apparently, throw like gods

I'm not sure how you're getting that impression. The quote you put there doesn't show up in the paper even once, and in fact if you search for "aimed throwing" you'll see several instances where they discuss the aimed throwing accuracy of the monkeys. Even in just the abstract there's a few places where they make it clear the monkeys are aiming (and additionally that's what they were measuring).

For both species we found positive correlations between target distances for throwing accuracy, direction and strength of hand preference, percentage of bipedal vs tripedal throws, and percentage of overarm vs underarm throws.

In fact, they go so far as to clearly state that the monkey throwing is a suitable model of human throwing, meaning that the way they throw is similar enough to us that we can actually learn about ourselves from it.

We believe that the capuchin monkey is an informative nonhuman primate model of aimed throwing in humans and that research examining the throwing behavior of capuchins provides insight into the neurological and behavioral characteristics that underlie coordinated multi-joint movements across the primate order.

Anyway, that's all the time I'm gonna spend on this mythbusting lol.