I do hft and this is bullocks. You can even trade cash fx with IB as a retailer and can make money and IB's interest is 100% aligned with your making money. And if you desire to get active in hft then you can apply for market maker status at various cash fx ecns and provide liquidity. What are you talking about?
I do both, hft and discretionary in various other accounts, for years on the cash fx side and make money. You should clearly delineate bucket shops from serious brokers and exchange venues.