XL6 why not XL7

Maruti did the right things launching this as Ertiga automatic was still missing some important features and it did not come with ZXI Plus. But according to me proper also give you 7 plus seating capacity. Ideally they should have given an option like Toyota offers with Innova. Secondly don't know why XL6 mileage has reduced as compared to new Ertiga. XL6 also has cruise control which was missing in Ertiga.