The Borg Queen wrote:
Surely trying to be Vulcan would have been more suitable for Data, right?
He can Logic with the best of them and doesn't have to concern himself with trying to understand emotions.
Trying to emulate a person is all well and good, but why a Human person specifically? Is it solely because Soong was a Human?
From a production point of view, it was so the writers could use Data as a way to explore facets of Humanity in a way that allowed the audience to gain a fresh perspective on them.
From an in-universe point of view, it might have been because Humans strove to improve themselves, to become more than they were.