If you're an HFT, you would much rather just pay for the order flow and not deal with all the shit that is retail (government, customers, all that shit). If you

If you're an HFT, you would much rather just pay for the order flow and not deal with all the shit that is retail (government, customers, all that shit). If you're some big retail firm, you're probably run by suits, way to beauracratic to run a difficult high-tech trading team, and any talent you got would get siphoned off to a good trading firm.