It just so happens that those who advocate and benefit directly from it are the ones who already have the power to make markets. The product of a company is based on its labor utilization, which doesn't change materially in the (very) short timespans of HFT. Liquidity aside, five minutes isn't going to make much of a difference when most people generally wait weeks or months to make major asset purchases like a car or a house, or to be approved for a small business loan. Only the ultra-wealthy car about milliseconds, because they can afford to make such vast and diverse trades in so little time.