It's jealousy that drives them. Think about it, both CCP China and modern India came about just after world war 2. At that time India was much more well endowed than China was with twice as much railway length for example.
Also much of China was war damaged, from war with Japan and civil war with KMT. In addition, the US was helping the KMT taking all the wealth and assets including gold reserves to Taiwan.
Chinese people were left with nothing and therefore very poor and starving. China was literally on its knees.
India's own superiority complex because it is a 'democracy'. Couple with western support and leeway which allows India to get away with annexing neighbouring states.
So when all these taking into account, Indians ought to be the next superpower that they aspires to be. Alas no, not only they are nowhere near superpower status. They found themselves behind the very people they had look down on all those years ago. So the red mist of envy set in.
Don't forget that the China's journey to prosperity is nowhere near as smooth as India.
China had to go through:
1) Famine and the Cultural Revolution of the Mao era.
2) Proxy wars all around its periphery.
3) Threat of war with both of the Cold War superpowers.
4) Relative international isolation until Deng took power. During the Cultural Revolution period, China could not procure arms and technology from both the West and the Soviets.
5) Constant CIA orchestrated operations in Tibet, Xinjiang, Hong Kong, and Taiwan.
6) Lower racial status than Africans, Indians, and Aborigines in the eyes of the White people.
What are the fortunes and challenges that India went through during that period?
1) Indo-China war: Defeated, but China didn't hold their gains and let's India off.
2) Indo-Pakistan wars: Victories, but cannot be compared to the scale of wars and disasters that China went through.
3) India was one of the earliest post-WW2 navies in Asia to have an aircraft carrier. The INS Viraat.
4) India was the first country in Asia to produce an "indigenous" supersonic fighter: HAL Marut.
5) India had inherited HAL, Ashok Leyland, Mazagon, etc from the British Raj. A great headstart way ahead of China, Japan, and Korea post WW2.
6) India had more far more international standing than Mao-era China.
7) India never really suffered from an embargo of arms or technology. They could always buy arms and technology from both sides of the Cold War at any point.
8) 1991 economic crisis. Really? Compared to the Cultural Revolution?
Since its inception, India went through a relatively privileged "childhood" compared to PRC China. Political support, technology, and, market opportunities were showered over this "golden child" of Asia. China, Japan, and Korea had to work hard, steal technologies, and innovate themselves to build their great economies.
Unlike China (and to some extent, Japan) the West was happily rooting for India to be the next Superpower. Many books and documentaries were published singing praises of India's "vibrant democracy", young demographics, English-speaking population, British legacy, bla, bla, bla...
Today, the "golden boy" of Asia is still way behind the great economies of East Asia. China & India had similar economic size in the 1950s. But today, China's economy is 5 x larger than India's and is still growing. While India suffered a 23.9% economic contraction.
China is the 3rd largest arms exporter in the world and India today, is still the largest arms importer in the world. What is India's arms exports share of the world's arms market? Negligible.
And the Indians are jealous of China? They should be ashamed of themselves! Instead of dreaming to commit another "Nanking Massacre" on China. India must go through a sustained period of deep humiliation. Only that could finally give them the kick up the butt to wake up.