Why do you think Congress didn't pass John Ross’ petition that 17,000 Cherokees signed?

Because the congress was interested in taking over the land on which the Cherokees lived to advance government plans.

Explanation:

John Ross's petition was made against the fact that he wanted to remove the indigenous people from their territories and put them to live in very disadvantageous reserves. Ross managed to sign 17,000 Cherokees, who opposed the forced removal that the government was imposing.

However, this was a losing fight, because as the Congress itself was interested in those lands, they ignored the petition, acting as if it had no value and ignoring the rights of the indigenous people did not approve the petition of Ross and the Cherokees.