The sacrifices only have to do with the worm inside of Oryx, Savathun, and Xivu Arath. As those three became more powerful, they required larger tithes to satiate the worms. Crota and his armies were a large contributor of those tithes which is why he felt it. The worm, though, is an entirely separate entity from Oryx's power over shapes. That power requires no tithe as he had taken it for himself. The act of taking is something the Deep respects as it show signs of strength. This is why the Deep finds an enemy in the Traveler as the Traveler freely gives and expects nothing in return.