Source: Suren
Traditional trader V3s got into usury, as did various V1 and V4 jAtis with large landholdings who took a new avatar as tax farmers. This broke the unspoken social contract. However, native V3 and V4 that engaged in usury largely escaped the scrutiny through their participation in ethno-nationalist movements as the thinkers and drivers.
The Chettiar-Mudaliar-Vellalar triumvirate of Dravidianism is a classic example. They were all moneylenders, tax farmers and bureaucrats who has gotten rich off of the British Empire.
They were having to contend with a new professional elite. Till Justice Muthuswamy Iyer in 1899, the Judges were Whites, the Collectors were Whites, business owners were white. So, the Naidus, Mudaliars and Chettiars were comfortable with this British elite. The rise of Brahmins, who were often their dependents back in the village, was a problem for them. The Brahmin leadership in Home Rule League and Congress was a problem for the British. Convergence of interests.
So, ego, business interests, power broking.