How not to practice law: charge the client six hours worth of time for the time it took you to prepare the bill

I've always thought that lawyers should not charge at all for the time it takes to prepare a bill.  That is not time spend on the client's representation.  That's time spend on office management.  But I know there are many lawyers who do include that time in their bills.  Here is the story of a lawyer who not only did what I think should not be done at all, he overdid it.  He was disciplined for, among other things, charging unreasonable fees and what made one of the bills unreasonable was that he charged the client charged the client six hours worth of time to prepare the bill itself.