Why is chapter 13 personal bankruptcy more expensive than chapter 7 personal bankruptcy?

In a chapter 13 bankruptcy, besides meeting with a client, attending the 341 meeting (that is the meeting with the bankruptcy trustee) there are 2 additional steps. The attorney for the Debtor must prepare and file with the Bankruptcy Court a chapter 13 plan and attend the hearing on plan confirmation. In a chapter 7 bankruptcy a plan is not drafted and filed with the Court and there is no hearing on plan confirmation so the legal fees for chapter 7 bankruptcy are less than for a chapter 13 bankruptcy.