On culture, IPC wasn't the outcome of Indian culture. It was the outcome of Victorian English culture. So we should be clear about what we are defending. Forget Kama Sutra and Khajuraho. It would be very difficult to argue that Dharmashastras (such as Manu Smriti) have strictures against homosexuality, as opposed to strictures against wasting one's seed (procreating for the sake of progeny) or corrupting virgins.
What are we supposed to have a national debate and consensus on? These are facts that can't be disputed. Contrary to its common usage, consensus doesn't mean unanimity. It means collective opinion, which translates into views of the majority. That was indeed the point of the Delhi High Court judgement, one should protect rights of minorities. Consensus is a red herring, we will never get that.
Section 377 needs repeal because it is non-enforceable and because there isn't a consensus.