Their anger is political - we have had very good relations with the Chinese since ancient times but they have been very angry ever since we gave refuge to the Dalai Lama which culminated in the 1962 border war.
These days the Chinese have also become very materialistic and power hungry like all other nations and hence would definitely not like to have powerful neighbours who can challenge their supremacy. One Japan is enough for them i suppose.

Chinas approach is clearly driven by strong strategic imperatives in the in the Indian Ocean Region, which would necessitate fielding of its military power projection capabilities into Indian Ocean in the coming decades. However, given the competitive and even adversarial potential of China-India relations, in these waters, it expects to find itself pitted against Indias potent naval power, possibly even in concert with the US.

For India on the other hand, it is critically important to balance Chinas rising power. By not doing so, Indias own increasingly eminent role as a regional power would be dwarfed. This would also have serious ramifications for Indias supreme national security interests. For example, this would make it impossible for New Delhi to negotiate the border dispute on equal terms with Beijing.

Indias strategic footprint in the maritime space adjoining Southeast Asia has been more discernable through its navys politico-diplomatic role as an instrument of fore ...more

China and india were never pitted against one another in history. china has evolved as a srong nation and naturally has ambitions to be regional leader. unfortunately, india is greatest threat to their ambition. we cannot be friends.

Our attempt to compare ourselves with them

Political game

Instead of Jealousy, they are very angry due to Two issues, One is Tibet, and the next is Dalai lama.