Yeah, "liquidity" is the standard bullshit distraction trotted out every time HFT is discussed here. Strangely enough, we've got "yummyfajitas" defending it again, which maybe, just maybe, might have something to do with the fact that he works in HFT.

As for liquidity, since the bots only make trades with the goal of shaving off tiny little slivers of profit on millions of trades, why and how would one of those sweaty guys ever buy anything from them? Even if one wanted to, the opportunity to buy might pass in a couple of microseconds.

All in all, working in HFT or even the financial "industry" at large, is complete bullshit. No self-respecting, decent human being should do it. No matter how you look at it, your mission there is to help world-raping scumbag bankers and the like make more money. They certainly don't need it.