Canon is great at market segmentation, and would rather get you to buy a great video camera for video needs than make a great camera that would barely meet your needs for video.
It's like Apple wanting you to buy a phone, tablet, and watch.
Sony makes cameras that do both quite well. With Nikon's acquisition of Red, they may also up their video game.
Canon is clinging to laurels that are long gone. And this is coming from a longtime Canon shooter who likes their still-image quality. They need an FX3 killer, pronto.
Sony is great at two things, marketing and sensor development. Their marketing is so great that everyone assumes they have 90% market share, where the reality is that Canon has approximately doubly Sony's market share.
Sony makes top notch sensors and fairly mediocre cameras, and sensor development is something that has been leapfrogged multiple times in history.
Nikon is the one that has a decent chance of dethroning Canon, unless canon ups their RF lens game.
It's like Apple wanting you to buy a phone, tablet, and watch.