There are a few reasons why these typical excuses ("we're providing liquidity to the market;" "We are eliminating market inefficiencies") which hedge funds continually offer to justify their own behaviour sound shriller and staler with every passing month. In this case they definitely don't hold water.
1) This system trades only in the very largest of large cap stocks, which are covered by the news media in massive rivers of text, and traded in oceans of volume. If it is fair to say that a trader in these shares would ever have to wait for someone wanting to make the opposite trade, it would be safe to say there were maybe only 5 dollars in the world. Arguably, adding more liquidity to these markets does not help, but actually hurts, the security and stability of the markets. We have learned that lesson time and time again.
2) We are dealing in microseconds here, and in a battle of speed between computers, all of which make trades faster than a human hand can click a mouse. it is no longer valid to say that waiting times need to be shortened, or that inefficiencies need to be eliminated, from a market like this.
These trades are ultimately mercenary in nature, and shorting massive quantities of a stock in a short time period like this is precisely what triggers sudden drops like the one we saw in the US recently. The Germans have it right, and and the hedge funds will need to find better excuses to defend the status quo which caused the financial meltdown of the past three years.