One reason that HFT is disliked is that it gives disproportionate advantage to the big players who put in the high speed infrastructure and equipment. This mean

One reason that HFT is disliked is that it gives disproportionate advantage to the big players who put in the high speed infrastructure and equipment. This means that a few companies are able to extract profits from the market by simply spending the most money up-front. Now obviously markets are not zero-sum games, but there is theoretically only a certain amount of growth returns available and some of this is being siphoned off. Couple this with the idea that the purpose of the markets are to most efficiently distribute capital to where it can be best used in the real world, HFT does not seem to be improving much.