Yes it is true that many Indian traditions have scientific reason behind them. Also in India season changes according to Hindi calendar. Our Hindi calendar is prepared on the basis of movements of planets and stars. Our traditions also have scientific reasons behind them. 

Despite all the scientific proofs about Indian traditions, we the Indians ( Majority) refuse to accept and dismiss as mere superstitions.

This is due to some fake people used religions as their business, and added their own fake thoughts in our old religious traditions. So people thinks that all these traditions are fake because of those false thoughts that are added by the fake BABA's and other religious persons. 

  Also during British rule, Britishers tried to destroy all Indian traditions and impose their own thoughts. 

one of the most important tradition which we usually learn from our childhood is doing NAMASTE to our elders whom we meet. And it is not done like that only it has some scientific reason also the reason is that when we join both our palms ,the ears , the eyes and the mind get connected together which makes us remember that person for a long time

Mainly due to Indian frame of Mind. Generally Indians think anything about India is primitive. Any rubbish from foreign countries is genuine.

These are the traditional practices that most of us do just like a habit, watching the elders, and usually we never look for the scientific facts behind them. But we do not know how they were originated in the society. It is possible that these habits were originated during some casual moments of life and later on we carried out research and created / identified scientific facts to support them. 

Whatever the reason may be, they became an integral part of life. The best thing is they are all scientifically proven ways.

All traditions do not have a scientific reason. What is scientific about not crossing a road of a cat runs across or not leaving if someone sneezes and so on.

I did not say all traditions have scientific proof. There many superstitions which do not have scientific evidence.