There is a Trader Joes with a apartment complex above it in Milpitas, CA (in the SF bay area). I've seen that in my city too but it needs to become more common.
I used to live in an apartment complex with trader Joe in the westwood area of LA near UCLA. Oddly enough, I would walk over to the whole food’s or Ralph’s instead to grocery shop (but everything was walkable, even the target across the street).