You're echoing the feelings of many frustrated DP's everywhere.
Basically, image quality is a multi-faceted and highly complex thing, and gestalt perception makes matters even more subjective and difficult to package neatly into catchy marketing terminology.
From a business standpoint, it's impossible to market something like smooth knees, or the idiosyncratic and intangible subtlety of film tones. It's much easier to create this delusion that "image quality can be wholly represented by a simple set of arbitrary numbers and specifications." What Canon is doing is no new trick: fool the consumers into respecting this arbitrary rating, then excel in that rating, thereby looking impressive in light of competitors. How do the competitors (Nikon, Sony, etc.) respond? They have no choice but to play along and join the megapixel race because when it comes down to it, consumers are lazy. They want things neatly packaged into a simple figure. They don't want to take the time to look at the bigger picture: the psychology of imagery, the subjectivity of art, and other properties that actually matter when it comes to image quality. "Oh, the Alexa only shoots 1080p despite having the most solid image of any digital camera ever made? Yeah, well it doesn't shoot 4k, which is essentially useless unless I'm indecisive enough to reframe in post or am projecting on a silver screen, at which point the difference is minimal at best."
Canon isn't stupid. They are a huge corporation that does its homework before investing in a product. They helped plant the seeds of numbers fappery and now they're harvesting the buds. If you ask me, we as the consumer are equally as guilty for being thickheaded enough to buy into such marketing BS as they are for proposing such an idea. When the goal is to make money, can you blame them?
