It's no wonder the shorts concentrate on running a stock down.
Well, yes. Shorting is, after all, betting that the stock will go down rather than up. But that is not what MMs do. MMs make a market so that YOU can trade, in whichever direction you like. The MM is always on the wrong side of market sentiment: when retail wants to buy, he must sell; when retail wants to sell, he must buy.
As noted previously, that MM is not a troll gunning for the little guy. He's a machine, calculating spreads and trying to beat out the competition for trades without losing money on them.
While news events occur on only 22% of the days in our sample, we find that short positions initiated on these days account for over 45% of the total profitability from short selling.
I don't think you understand what that means. It means that shorts open positions on bad news, and profit by doing so. Not exactly a revelation.