Why was Theroux unwilling to explain his first impressions of India to Vishnua Bhardwaj, the Accountant General on the train to Simla?

Theroux had already been finding India overwhelming in its poverty and filth and had witnessed children taking the remains of his breakfast. He was thinking about Mark Twain's observation that all things except human life are sacred to Indians, but he was afraid of offending Bhardwaj, with whom he was having a pleasant conversation. In addition, Bhardwaj was obviously an honest and hardworking man who may have been put off by Theroux's unasked question.