In this case, it WAS objectively rude for the IO to say that couples are expected to have children after a certain amount of time. He had no idea if OP is/was capable of having children or if they even wanted to. It's a personal decision to have kids or not and a couple isn't legally less deserving of approval if they don't have kids. If they have kids, great, show their birth certs to the IO. But for an IO to show their prejudice like that is highly unprofessional.