I can appreciate your reasoning. I know you aren't suggesting this, but the popular blanket conclusion that HFT is bad because anomalies like "flash-crashes" sometimes occur is misguided. It's equivalent to saying we should outlaw highways because of an occasional traffic-jam or 12-car-pileup. On the whole, the benefits to the economy (and therefore, individuals) resulting from HFT far outweigh the costs. It's never a good idea to throw out the baby with the bath water and I've yet to encounter a nuanced mathematical argument (backed by concrete data) to demonstrate how the economy is harmed by more efficient markets.