You seem to have a lot of animosity- did you post in this thread to just have a circlejerk about how obviously bad HFT is? Or have a reasoned and informed discussion?
Maybe my reading comprehension is off- here is your second sentence: And none of them benefited society in any respectable proportion to what they earned. So why should society infrastructure be modified to suit them (exclusive order types on exchanges regulated of necessity) ?
You don't even know how much they earned, so how can you really comment on it? Virtu Financial recently filed an S-1 to go public: https://www.sec.gov/Archives/e... Total revenue: $664 million. Net revenue: $182 million. Not bad, but not exactly killing it either.
What are you talking about with "society infrastructure", and particularly "exchanges regulated of necessity?" What does that even mean? Did you know that NYSE, amongst many other liquidity venues, is now a publicly traded company? The exchanges have provided these order types of their own volition, this isn't an "HFT" problem, its an exchange problem if anything- they are trying to attract the HFT flow to their exchanges!
As for "off the shelf" and "more difficult", it is nuanced. There are many components that are required to build a trading engine, major pieces of them can now be bought- low latency market data (Exegy), low latency network cards (Mellanox/Solarflare), and exchange connectivity, for example. There is now a critical mass of developers who can build this stuff for you, as opposed to this being arcane research type stuff. However, its all rather expensive. Co-location itself will cost you $10k/month per rack last I looked into it. Hence the "high barrier to entry" and "off the shelf" go together. 15-20 years ago, a boiler-room type phones and brokers operation might only have startup overhead (outside of employees) in total of $10k per month. The costs of some of this stuff will come down as it becomes commoditized, but bandwidth and datacenter space are likely to remain a sparse resource and remain costly.
As for whether this new technology is benefitting anyone, I would argue this is just a luddite argument that has been made many times before whenever there has been a disruptive new technology. Do you think the guys on the floor of the NYSE used to pay hundreds of thousands of dollars for their seat because they liked going to Champs Deli or because they could wear a funny colored blazer? They did it so they could trade on information first. Telephones disrupted the bucket shops, SOES bandits disrupted the floor traders, later electronic trading completely disrupted floor trading, and now we have a bunch of guys who realized that they could build much faster infra and make money off it, and they did, forcing others to beef up their systems to keep up. And most have.
I am not spouting off anything- I spent the last ten years building this stuff on both the HFT and Agency side. You read a few articles, and maybe the entire Flash Boys book? Good for you. I am trying to give you the rest of the story.