Reasons:
-relatively powerful yet fuel efficient engine
-smoother suspension (as compared to Honda City)
-looks better than the City (the back/trunk of City looks weird)
-at the extreme, the handling is better and more predictable.
Regarding the 7-speed tranny of the Honda City:
It's basically a toy. After playing around with our Honda City 1.3L 7-speed, I ended up just putting the shifter to "D".