I am a small retail trader trading with one of those brokerages you mentioned. I like their platform and the service my broker provide and see no reason to switch to IB.indeed. I must have misunderstood the meaning of "retail investor", which I know I haven't. Retail investors as no-account minimum customers of brokerages like Etrade, Scottrade, TD, Schwab,... and smaller ones with highway robbery commissions like $6 flat. Why would investors who can't afford the $10K minimum of IB be offred those instruments? Some of those aforementioned do not even offer market data.
I call them churn-n-burn and pump-n-dump, they just want cash flow on the books.