If MM's were illegal, you wouldn't be buying or selling stock. They are the ones that actually conduct the trades for us. Without them, you would have to find a buyer if you were selling.
That article was not about MM's anyway...it was about TRADERS that manipulate the price by well-placed sells and buys to force the price up or down. I have said, for years, that it is TRADERS that manipulate the prices, not MM's, because MM's get paid regardless of whether the price is increasing or falling. All they care about is that there are buyers and sellers. I know many think MM's manipulate prices, but all they manipulate is their spread, and they make money on every single share traded - buy or sell - rising or falling.
Traders can manipulate the share price easily, if they have enough shares - I could tank some stocks I own if I wanted to - if you have over 100M shares of any company, you can set up sells at some limit that will literally never let the price go above a certain price until all the shares are sold. I have 250M shares of one company...