When the profiler is enabled on a database, a collection DBNAME.system.profile is created on single shards. Given that the collection is local, it is not considered movable via moveCollection nor via movePrimary.

When transitioning to dedicated config server, collections/databases are moved off via moveCollection/movePrimary and then this check makes sure that no collection on user databases is still containing data.

Since the profiling collection is always skipped, transitioning to dedicated may fail because of that.