Who said you this kids story of 1970. Is that the vaatal and kannada extremists?
Even the term "KARNATAKA" was used by the British to divide india by south-north where they believed starting from KTA is south. It was a failed attempt. The success was hindu-muslim.
So how the centuries old South Indian classical music is called upon 'karnatic' pairing with 'hindusthani'. The South Indian classical music was named 'karnatic' while in british rule as again their believe south starts from KTA.
And what 1970, 1980, 1990 is to do with. Just go and listen to speeches of pro-kanndiaga-extemist elements and sure will grow up a ture goonda.