While I agree that CC are designed that way if used responsibly they can help you out. For eg you can save a few thousand rupees every month when shopping for groceries gas etc.
Those can go ahead to something I might want or need. Since these things are fixed expenses and I HAVE to pay them each month why not capitalize on them.
They are used much more widely and help a lot in Europe and North America so why not here.
5% Cashback is pretty decent when doing grocery for a big family like mine and I am just referring to supermarket stuff here like imtiaz or naheed etc 
Also I don't mind getting 20% off at a decent restaurant like Arizona Grill with my family. 