Tamil = Sanadhana Dharma
In ancient times, Tamils worshipped nature, they offered Pongal to the Sun, worshipped planting stones (Hero stones/Nadukal), worshipped a female deity named Kotravai, worshipped village deities like Karuppar, and worshipped their clan deities (Kula Deivams).
All of these worship practices exist only within Hinduism today. Followers of Abrahamic religions have discarded all of these and moved away.
Now, if I invite people to worship only the entities I mentioned above from now on, Hindus can easily do it. But for followers of Abrahamic religions, it is haram (forbidden).
Therefore, first stop lecturing Hindus to worship the deities that their ancestors worshipped.