I don't have any more or less dislike for HFT over more traditional trading. My biggest problem with finance is the brain drain it creates, in HFT's case a lot of great maths and computer science people get sucked into the finance black hole which saddens me greatly. Certainly having liquidity in the market is important but what level of liquidity is enough and beyond that no more value is provided to society and so the brain drain in fact holds back society?