Traditionally classical music was passed through generations within families. So a few communities such as Devadasi, Barber or Brahmana - took to music more often than others. But that does not mean others did never get in. We can show such instances.
There is a reason why Tanjavur became a cradle for music
Not all deserving people got deserving credit. Get on with it
You can blame it on the Chennai ecosystem. But you may also ask, what prevented Karnataka & Kerala to develop a better ecosystem!
The writer of Bethehem Kuruvanji, needed the artform to reach his target audience.