Wrong.
Tax fraud doesnt exist if you declare the income, even if ungainly got. Al Capone didnt declare his criminal income so he got prison.
The crime of fraud is making a representation that induces someone to give money with the intent to deceive. Telling someone to give because no money will go to the organizers wheN In fact There was already an arrangement to split proceeds and therE is a monetary loss is fraud. It matters not if some good was done. Telling the lie to get the donations with the intent is sufficient.
That would explain why the individuals were not prosecuted for tax fraud based on a failure to report the income, but your statement is simply not true. If the charges against Bannon and his associates are accurate, then this would seem to be a classic case of tax fraud simply for registering a non-profit organization on fraudulent grounds.