Do you mean the Chris Stucchio piece? Because, despite it being an apology, it doesn't justify how HFT is socially beneficial. This piece makes hand-wavy claims about liquidity, and says that it will better justify HFT in a coming blog post.
As for the Bloomberg piece defending HFT, it fails to address a few issues that the SEC and critics have with HFT. These issues are enumerated in the Ritholtz blog post. Pointing out certain facts that an argument ignores is a valid rebuttal.
Could he just maybe write a post and spark a discussion about how his field actually works so we can learn something about it?
I DO NOT UNDERSTAND this HN mentality that equates "learning more about X" with "joining the death cult of X". And it comes up all the time: no, we can't discuss how SEO works, because that would make us morally black hat SEOs; no, we can't discuss how HFT works, because that would make us morally Goldman Sachs executives; no, we can't discuss how a law is written, but that would mean we want to give the Internet to the MPAA.
The particular mode of argument in your comment and many like it on this thread is directly counter to the whole idea behind this site and every other worthwhile message board on the Internet. Yes, we get it, you don't know who G.H. Hardy is or didn't pick up on the joke in the title --- but it's obvious from the rest of the post that it's trying to explain how things work, not make a case for why it works that way.
The word "liquidity" doesn't appear in my blog post.
All I made were very concrete claims about how a matching engine works (all of which you can verify from the sources I listed) and some explanation of how why being faster helps HFT's to make money.
However, I was still looking for the justification promised in the opening sentences. So I look for the subtext in your technical explanation that would justify this oft misunderstood field. I clearly misunderstood your justification for HFT. What is your justification for HFT?
From paragraph -1: "In future posts, I’ll discuss it’s societal utility and costs."
Perhaps to those that already understand the significance of those facts. But to people who want to learn, it's not useful.