Last time I checked, banks are the most powerful industry, and GS is the most powerful bank. Aleynikov was single handedly building, deploying, maintaining and updating Goldman-Sach's HFT framework.
If you believe that key people like Aleynikov don't make the HFT industry profitable, a certain Medallion Fund and a Dr. James Simons would beg to differ.
I don't know of any big software companies getting government bailouts after gambling with money they scammed from average citizen . Once you can get away with that, and not have a single executive do jail time, come back to me. Every industry is subservient to the whims of banks. They'll tell you otherwise, but actions speak louder than words.
I call shenanigans on the claim that Aleynikov was single handedly running the trading infrastructure for even a single one of their desks. That's complete nonsense.
As for Jim Simons: It's generally believed that the main cause of Renaissance's success is that they have a couple hundred of the world's smartest people all working together. It's not a 'key man' shop at all. (Also: You seem to be suggesting that Simons himself did all the work. The fact is that he spends most of his time smoking cigarettes and handing out wads of cash.)