cannot add a field to values section on a pivot table in Excel

Creating measures is not a challenge but what's the rationale for this? It's extremely inefficient if I have to create a measure for every field I want to use as a value in my pivot table. The fields already exist in the database and they are already assigned as SUM fields. This is completely backwards and makes the Analyze in Excel feature useless in many cases. v-haibl-msft can you please explain the technical reason for this?

Thanks,
Mick