If not pastas and white rice, what should one eat? Kebab? Ice creams? burgers? There isn't a source of carbohydrates better than pasta and rice
To be specific, are you asking just in general, or do you mean, in relation to brown rice and whole wheat pasta? I usually do brown rice, whole/wt pasta for the fibre and extra nutrients. Plus they are keep you full longer. Good if you're trying to maintain a lower weight. Some more radical opinions will have you believe that whole grains will kill you. I'm open to any reasonable opinions, but to date this is stilll an opinion shared by few.
Brown rice and whole wheat pastas are usually healthier as mentioned above. A good source of carbs is also whole wheat breads