The fact that the activity has been happening for years doesn't invalidate that it could be bot related. Also the fact that reddit admins had to change their site algorithms to remove it from aggregated results, because posts were being gamed to the front page, implies that the behavior was not normal human traffic.
> Also the fact that reddit admins had to change their site algorithms to remove it from aggregated results, because posts were being gamed to the front page, implies that the behavior was not normal human traffic.
It implies it's unusual traffic, but it does not imply it's inhuman traffic -- doubly so because the difference has already been explained in a way that doesn't require invoking bots.
Somewhat amusingly, after r/the_donald discovered it could push pro-Trump memes onto r/all by making every post on the subreddit about upvoting content, some other subreddits managed to pull off the same stunt in protest.
