Apparently HFT is going to bring on the next crash or something

I confess, I do find myself a little puzzled by the coverage of finance and banking over at The Guardian at times. Are their writers actually inhabiting this same universe that we are or are they phoning it in from some parallel one? Tke this example, worrying about the perils of high frequency trading (HFT):

Cynics may conclude that Goldman's damascene conversion is a PR exercise designed to counter some of the more incendiary material that Lewis is expected to disclose. But they would be wrong. After playing a heroic role in the sub-prime mortgage scandal and Greece's economic ruin, Goldman, like all the big banks, is surely now turning over a new leaf. This is just as well. The consequences of a repeat of the 2008 financial crash, conducted at warp speed, are too terrifying for us mortals to get our heads around. History repeats itself first as tragedy, second as farce, Marx observed. But then he didn't have fibreoptic broadband.

My first confusion is that of course it wasn't trading, at high frequencies or not, that actually caused the crash. The markets that do have high turnovers, at high speed, are things like foreign currency, options, derivatives, and now moving into equities. None of these causwed the slightest problem during the crash. That was all about housing finance, the securitisation of mortgages into bonds that were then sliced and diced. Abnd, notably, very rarely traded after they have been placed with investors.Almost all of these bonds were nearly entirely illiquid, no one trading in them at all a month after issuance. And that's what caused the problems given that some banks had held onto healthy slices of these issues. How we can comare the perils of HFT with something that was hardly traded at all I'm really not sure.

As to why Goldman Sachs might not like HFT, can we at least start with the idea that GS is a greedy, profits hungry, capitalistic firm? Good, thought we could get agreement there. So, what's the effect of HFT? It reduces trading margins: reduces the difference between the buy and sell price of any particular security. Who would be unhappy if this happened? The people who make markets, the people making those buy and sell prices of course. A large part of GS's business is in making markets in things. And if margins collapse as a result of more trading and greater liquidity then GS isn't going to be happy, is it?

But over in Guardian world things seem to be different....