Hey there! First time poster, long-time reader (as long as this forum has existed).
My take on it is that... Canon still makes great cameras. The 70D is a great camera. The 7DII is a great camera.
But beyond *just* making a great camera... they've really failed to innovate.
At this point Canon should've had 4k in a DSLR before anybody. They should definitely have had something out to compete with the Black Magic section (or at least have added the ability to shoot RAW video natively in the firmware on the 5D, 6D, and 7D cameras), and they really need a compact solution to the hell that Sony's about to rain on them with the A7ii line.
I think the problem isn't, so much, that Canon has done anything "wrong"... they just need more cameras to cover a broader and more divergent user base.
It isn't just "pros and consumers" anymore. There are a wide variety of people out there with specific needs. There's a customer out there who's looking for exactly something like an a6000. There are budget videographers looking for something exactly like a GH4. And all the pros are going nuts over the A7S.
Canon has the technology to build a camera at each of these levels. Sony not including in-body 4k leaves the door wide-open for Canon to make a camera that competes better with the GH4 (before Nikon throws one up there). And the 6D is way overdue for a refresh (Nikon has already had the 600, 610, and now the 750 while Canon has been stuck in neutral.)
They need more full-frame solutions, more compact solutions, and their video performance is long overdue for some new codecs and upgrades and 4k definitely wouldn't hurt them as it's quickly becoming the standard. Just throw it in there before Nikon does and everybody will be happy.