I dont think rs made a veiled attack. It was an open attack on people nitpicking with IR's singing as "elitism". Personally, inspite of being a 'sangeetha gnanasoonyam' I myself find IR's singing wanting at places. But on the flip side, he is a "successful" popular music singer. His diction is good, he emotes well and connects with the listener. Whether you and me like it or not, there are thousands or even millions of people who enjoy and appreciate his songs and singing. We can say these people dont know much about music and that is why the like his singing. And this is what I think rs calls - "elitism".
Anyways, I hope none of us have the impression IR does not appreciate or give importance to "shruthi suththam". That he even almost made BMK sing on stage the 27 swara sthanams shows he is aware of his limitation as a singer (otherwise he would have demoed it). He has introduced great singers, and used great singers to sing great songs. Only when the situation warrants for emotions more than technicalities or if the pro singer is not available he has sung. So let us stay focussed on this criticism.