INDEX BY doesn't work for selects with scalars only

By scalars-only-selects I mean this:

SELECT c.id, c.name FROM GLocalityBundle:Country c  INDEX by c.id 

The result won't be indexed by c.id, as opposites to this:

SELECT c FROM GLocalityBundle:Country c  INDEX by c.id 

Assuming that GLocalityBundle:Country has several hunders of fields, and you need only two of them, this is very disappointing

After diving in the code, due to rigorous separation of entities on objects and scalars, it looks practically impossible even to implement this feature
What is this? Bad design?