Are Canon's APS-C Sensors Really Worse Than The Rest?

One of the more significant concerns of many a photographer has always been about Canon's APS-C sensors. Though their cameras are dwarfed by the likes of Fujifilm, Sony, and Nikon, they have always marched to their own drumbeat. While the rest of the industry goes with 1.5x crop sensors, Canon has forever gone a bit smaller with 1.6x crop. It sometimes worked to their advantage when translating their focal lengths over. But has the quality always been worse?