Even if we consider city has low fuel average than Swift (true)
A difference between 12km/L and 14 km/L is not that huge if former is a better car.
Eg City aspire 1.5 vs Swift GLX. Former is better imo. A lot more room and power, most features are also same except a few.
But then again, there are people who love driving that dabba Alto even though they can afford better cars just cause it has better fuel average. Anything for an increase of 3-4km/L