Not a great feature as that would could lead to people asking other people “HeY, wHy YoU nO uPvOtE mY mEmE?!,?!!1!1!11?1!” And could cause large fights over a button that takes a few seconds to click if the user’s ego is fragile enough. Furthermore, they got rid of the visible upvote to downvote ratio, so I doubt they would add something like this.
