I will give you that there are some big banks getting into HFT now, and that's a different story, but a statement like "HFT in its worst form amounts to high speed computerized rumor mongering." is wildly inaccurate and shows a complete lack of understanding of the industry.
Furthermore, there is a massive difference between algo trading and HFT. Technically speaking, yes, HFT falls under algo. However, HFT is about speed and making very little profit many times throughout the day, usually by providing liquidity.
Algos on the other hand, especially things like high end models aren't meant for HFT because they take larger amounts of time to run (ie: backtesting). These are used (for example) to determine misprices in the market that will pay off heavily in the long term, or (as others have mentioned below) to buy/sell a large quantity of shares in a way that it won't move the market in the other direction, rather than make an immediate, albeit tiny, profit.