How is HFT different than traditional arbitrage except for the fact that it is faster and potentially at a scale that normal traders would never be able to keep up with? How is buying something one second and selling the next inherently different than buying one day and selling the next? Speed?
Does computers being faster make it any more unfair than when one trader has access to millions or billions of dollars when I only have access to hundreds or thousands? I don't think so.
Now, one could argue that HFT disrupts the way that Wall Street has worked for decades, but really, it is shifting the profit from traders, bankers, and fund managers to HFT firms. Sure, Wall Street probably doesn't like it, but does anyone like it when someone disrupts their market and takes their profit?
You could also argue that HFT doesn't add value because HFT firms inherently don't do anything other than trade millions of stocks only for the sake of trading them, but how is this worse than day trading or running any other fund other than the turnover rate?
Perhaps I'm blind to the real issues, but I just don't see a huge difference between HFT and traditional Wall St. trading, except maybe that it magnifies the problems inherent in the system due to speed and scale.