Couldn't agree with you more. The question surrounding HFT should not be: "is this perfect?" , but instead should be: "is this better than before?". And also,

Couldn't agree with you more. The question surrounding HFT should not be: "is this perfect?" , but instead should be: "is this better than before?". And also, I'd point out that it takes hundreds of thousands of dollars to start a bank as well. Do existing banks have an unfair advantage over prospective start-ups due to these barriers to entry? Of course, but that's pretty much how the world works everywhere. It's not specific to HFT.