Quicken allows users to clean up their category and payee lists by editing them without affecting prior entries. This allows users to unclutter their global category and payee lists so those categories and payees actually in current use are the ones that remain visible for entries.
In many cases, a payee is used only once, so removing that payee from the global payee list allows users to choose from a list that is not cluttered with one-time-only payees.
In MW, if payees are deleted from the global list, the payee information on the individual entries associated with those payees is also deleted!
SUGGESTION: Uncouple global payee/category lists from account entries so editing of the global lists does not result in entry-level deletions.
We most likely will not be implementing this in the nearest future. We believe that storing all of your data in MoneyWiz is the way to go therefore we do not plan to implement the ability to remove categories/payees without deleting them from the transactions.
Perhaps we will come up with a feature to archive payees but not for categories.