HFT is hugely expensive to maintain. Staffing and equipment costs are massive.
HFT choose not to trade on exchanges with delays because they want to exploit latency advantages. That's why govt should regulate this on all exchanges to just wipe it out.
Consolidation is not good because it will collapse into a monopoly. Which will require regulation also, because markets do not "work" on their own.
I'll check back later, going for a walk outside now.
----
Here is my reply, despite not replying for 40 minutes, I've put something about capitalism on HN which immediately gets you a fake "you're submitting too fast".
Cannot post any more after that because HN doesn't like discussion unless it's about a tiny window that they agree with. Perhaps someone flagged my comment - if so they make this board a far more boring place to be.
---
HFT != electronic trading. Many firms are automating front-to-back, that is unequivocally a good thing. HFT is latency arb.