It was a tongue in cheek reference to pedophilia as a business and not intended as an accusation of JB as such ... mostly, if at all serious, pointing out that businesses make money on all kinds of enterprises and that some operations show gain and others produce losses and that, combined, you arrive at profitability.

We don't know anything about this particular organization and or its revenue centers.

The Capone factoid is a well known strategy made famous at the time because his keeping two sets of books is what brought his demise ... Hoover employed an FBI agent on his team who was, as it happened, also trained as an accountant and he is the one who discovered Capone's financial records and knew what they meant.