I expect it’s a feature hangover from days of old, and MS can’t / won’t remove it. Some customers use the Resource column to indicate Ownership of a task, and hence ownership of a Summary Task indicates ownership of the phase/workstream etc as indicated by the summary task. If you are don’t care about monitoring or tracking Work, the it is *okay* to place resources on Summary Tasks. The alternative is to use a custom text field called Owner which is my preferred method.
