A lot of skills can get you in public life: social work, showbiz, journalism, literature, music, painting, politics, research, education, etc. A very simple law of human traits (not just Indians) is that we tend to pay attention to two kinds of skills: (1) the ones that are easiest to comprehend, or (2) the ones which everyone else is paying attention to.
There is a universal set of people, that are able to comprehend entertainment. The subsets of people understanding different skills get smaller as we move from sports like chess, to literature like cartoon strips, to stuff like politics, research and education, and high-quality literature.
The entertainment sector is very easy to comprehend, even if you are a world-class mathematician. Most movies feed you a story where you don’t need to apply much of your brains, and hence actors and actresses find it slightly easier to make way into public sentiment than academicians.
The sports sector is also very easy to comprehend. But cricket receives more attention in India than other sports because cricket is what everyone else seems to be paying attention to.
Even humans of higher intelligence find it easier to watch movies and sports than to solve tough mathematical problems, and that is why entertainment is often a way for them to relax.
Science and mathematics fields are not easy to comprehend for the general populace. There are those who find these easy, but would still prefer to find easier skills to consume. And hence, they seem to be underrated.
Originally posted as an answer to this question on Quora: Why are scientists and mathematicians so underrated compared to film stars in India?