Sports arguments compensate for our powerlessness. We will never be permitted on the playing field, court or ice to change the outcome of the game – and even if we were, we'd be toast – so we soothe our nerves by preemptively doubting the efficacy of a play, screaming at it as it happens and second-guessing the whole thing when it's done. Then, because God is unfair, we lose anyway. The loser has even more reason to argue, if only because a verbal battle prosecuted on its behalf is the only thing his team can win anyway.
And if you lose – I mean, really lose – there is no argument more fulfilling than that of who has the worst owner. Because if you can make that one stick, then everything else explains itself: bad players, coaching, drafting, trades, talent evaluation, conditioning? Well, you know what, the owner picked those assholes, or he picked the asshole who picked those assholes. He is Lord High Asshole of His Asshole Realm.
Each asshole's sports kingdom doesn't exist in a vacuum, however. If sports were the only criterion, then the worst owner would be the one with the worst winning percentage every year. These people live in the real world, too. They bilk the public for tax breaks, exemptions and steep discounts on policing; they ignore impact and destroy surrounding infrastructure; they hold municipalities hostage; and they sit on their asses and reap millions annually in shared revenue while plundering young men (often of color and often from poor backgrounds) of their health and condemning them for wearing baggy pants, having tattoos, being "greedy" and "wrecking the game."
As such, the correct answer to who is the worst owner in sports is all of them. Unfortunately, pulling the ripcord here and floating out of the frame is not a practical response. This is not 'Nam; this is a listicle. There are rules. The following are the worst owners in American sports, in more or less increasing levels of boobery, mismanagement and personal/social vileness.