The supporters were not there either because they are brahmins, chettiars, or Kshatriyas!
If the influential sections have to remain influential there are only two options: 1. Either defeat the British and throw them out or 2. Align with them and stay put in the power structure.
That is what the intelligentia (brahmins) businessmen (Chettiars) princely state rulers & Nawabs (Kshtriyas & Muslims) had done after failing in defeating the British. Their being Brahmins, Chettiars, Kshtriays & Muslims is purely incidental!