This system seems inherently flawed, is there a breakdown somewhere why this was the design decision?

If this site acts anything like reddit, people will at a point jump in the downvote train and will be "unfairly" downvoted en masse. If the upvote button next to the downvote doesn't offset that I expect we'll see a lot of negative reputation.

Maybe it's a technical hurdle or something -- and it's not like it's that important anyway -- but kinda seems just strange to me.