I think you are still confused about what constitutes money laundering. Accepting money from a criminal in exchange for goods or services is not money laundering, yet your whole post is about that.
Like, let's take the complication of know your customer out for a second. Of course you should not be prosecuted because a bank robber comes to your store and uses the money he stole to buy something. But if you are keeping fraudulent books in a cash-heavy business to conceal the source of tens of thousands of dollars you or your associates made through criminal activity, why shouldn't it be a crime?
Like, let's take the complication of know your customer out for a second. Of course you should not be prosecuted because a bank robber comes to your store and uses the money he stole to buy something. But if you are keeping fraudulent books in a cash-heavy business to conceal the source of tens of thousands of dollars you or your associates made through criminal activity, why shouldn't it be a crime?