I know that many say, Clark shouldn't be portrayed as human
Those people should be smacked in the head with the annual edition of the Daily Planet. He most certainly should be portrayed as a human.
As I said, the main issue with the characterization here is the lack of balance. It's by no means necessary (quite the opposite) for Clark to know he wants to be a super-hero from the get-go, but he should be shown gradually growing into it. There is a bit of a light-switch logic in Earth One, burdened by a little too much gloom from Clark's perspective of his life for the biggest portion of the story.