I actually feel sorry for Canon (and Nikon). It seems like they have a real dilemma.
Flagship cameras are essential to their business model. But, these cameras take a considerable amount of time and resources to develop. Technology is changing so rapidly that they run the risk that by the time the research, development and testing cycle is complete, the camera ends up lagging behind on technology. But, if you rush it to market and there's a problem, your reputation is shot.
On top of all that, when your customers are spending $6,000 to $8,000 they expect a camera that is going to be state of the art for more than six months or a year. It's one thing to spend $1,000 on a camera and then have it replaced with a new model in a year. It's quite another to invest $6,000 in a camera that feels obsolete after a year.
I seriously doubt that these high-end cameras represent much if any profit to either company. They need them to maintain their reputations, but they can't be big profit makers. And, to make matters worse, they have to devote resources to these models, while constantly fending off challenges to their other lines from companies like Pentax, which desperately want a piece of the high-end "prosumer" market.