Murthy is 100% right! Even in Olympics, they play instrumental versions of hundreds of national anthems, including those of the G-7 economic super-powers. The politicians are just trying to get some political mileage from this.
The Instumental National Anthem is just the same as the vocal one. Moreover, Murthy is a person who deserves a lot of respect for what he did for improving India's economy ! He is a real patriot, unlike the ignorant politicians and advocates who sing the anthem and then do absolutely nothing for the country. Lets accept sagacious advice from Narayanmurthy.