Kissing in public is culturally unacceptable in India, TC -- hence no kissing in Bollywood movies, and actors like Aishwarya Rai who also star in Western movies have a "no kissing" clause in their contracts because it would ruin their Bollywood careers if they kissed on screen.
I think the point is that RG isn't just some tourist who blundered in acting inappropriately. He visits India a lot, he must know how it's seen, but he does it anyway and that has got to piss a lot of people off that he's deliberately ignoring their standards of what is and isn't acceptable. "Being a smug git" not being actionable, they've gone for the obscenity angle...
Also very unfair to Shilpa Shetty who was definitely the kissee rather than the kisser but whose career could be very negatively impacted.