I don't think that's entirely correct. They are profiting from information asymmetry. Markets change slightly and they know it 1 millisecond before everyone els

I don't think that's entirely correct. They are profiting from information asymmetry. Markets change slightly and they know it 1 millisecond before everyone else. In that millisecond they buy or sell and profit from the price change. This is stuff that would have been done anyways by regular traders. It's just the high speed traders are now faster and so do it first. As far as I can tell that isn't hurting anyone more than normal arbitrage.