Two important points to be considered now.
1. How do I say that most of the Hindus are Smartas?
Take the case of Bengal. Sri Ramakrishna's family deity was Raghubir (Rama). His Tantrik Guru was Bhairavi Brahmani a Vaishnavite Tantrika. He worshiped Krishna and Kali. This is Smartaism. Most of the Brahmins in Bengal are like this.
Kerala: The Nambhoodiris claim to be Purva Mimansa followers. But see the worship. Shiva, Devi and Krishna temples are all over Kerala. Everyone goes to all these temples. Swami Chinmayananda spent his lifetime spreading the message of Bhagavd Gita. But in all his Ashrams the central temple is Shiva's temple. This is Smartaism.
2. Some one might say that "But there is proof that Smartas are Saiva, Vaishnava". This is exactly what you are supposed to believe. Smartism is Saivism for Saivas and Vaishnavism for Vaishnavas. All things to all people is the name of the game. We cannot claim that Smartas are pure Advaita Vedanta people. Pure Advaitins reject Purva Mimansa. They do not subscribe to Sri Vidya practices which basically believes in Saguna Brahman.
I would also like to point out the all important role of the Sankara matams and thousands of other matams which are loosely affiliated to these matams. These matams have spread the idea of non-sectarian Hinduism all over India. They have also revived the Vaidic practices.
Again India has been known for the millions of wandering renunciates. Smarta religion brought some order here also by creating the Dasanami Sampradhayas of Sannyasis. They created a semblance of an organization. But this affiliation is only nominal. They do not even have a uniform practice of dealing with the dead bodies of Sannyasis.
If Smarta religion is so good and has strengthened Hinduism how come no one is talking about it?
Here lies the crux of the matter. Smarta called themselves Smartas because they wanted to emphasize the role of the Smiritis/Dharmasasthras. Dharmasasthras are founded on Varnashrama Dharma. So the Smartas have been accused of propagating the Varnashrama Dharma.
But this criticism does not take into account the seminal role played by the Smartas in strengthening Hinduism and preventing it from becoming divided into a number of warring sects.
The vision shown by Adi Sankarachrya or Sankaracharyas is unparalleled in the history of Hinduism. We can only pray that such a visionary will be born in India again who will unite all the castes together, so that the caste name would signify only a tradition or culture. A Dalit should say proudly of the Brahmins "Here are the people who have kept OUR Vedic traditions alive."