How Canon can ignore the market when the technology is there is beyond me. They created an entirely new product and idea accidentally, but are now intentionally turning their back on it. IMO they will come to regret this decision with Sony, BlackMagic, and the likes dominating. Why would I purchase a C100 for twice the cost of a A7s? The two have offsetting features/outputs, but ultimately the Sony delivers far more value and image quality.
Then get the A7s.
Canon isn't trying to market toward the cutting edge of hobbyists, but toward wedding videographers, low end corporate, etc. That's why their mirrorless segment sucks for stills, too; they're focusing on products designed for professional shooters, who don't need that extra DR but do need that killer autofocus and optical finder and lens compatibility. When they throw that out, you get a sorry consumer product in the EOS M. Whereas the 7 DII looks fantastic.
That said, the A7s has a dreadful interface and ergonomics for shooting video, poor lens compatibility, a non-standard codec that's less industry-friendly (if arguably better) than on the C300 or C100, and Sony's SLOG 2 implementation is awful with over-saturated highlights that can't be fixed in post, odd skin tones, and too much dynamic range for an 8-bit wrapper. And the skew is just dreadful, not a nice combination for a lightweight camera. I find the image far inferior subjectively to the C300, but technically it is great and the low light knocks everyone's socks off.
I spent a lot of time with the F5 and while the specs blow the C300 away, the user experience was really poor. Bad timecode sync, ugly colors, magenta skin, ugly grain structure, SLOG 2 sucks (SLOG 3 is better so kudos to Sony there!) wheras WideDR and the current Canon Log color matrices are really nice and very pretty, etc. It was like driving a car with a lot of horsepower but terrible handling.
Canon's the market leader so they're focusing more on boring "pro" features that make the camera easy to use and with footage that's small, easy to ingest, and edit, and can even look ok straight out of the camera. WideDR looks great and has lots of DR; EOS standard intercuts with Canon dSLRS, which are still ubiquitous, even on network tv as b cameras (seriously). Sony has great specs but takes more work to make it work and it's not there when every MB and transcode costs your company serious time and money. For an enthusiast, seems like a no-brainer to get the Sony, the low light is incredible and if you avoid clippy saturated highlights and skew then the image is very competitive and better than Canon dSLRs for sure (if you can grade well). But for bread and butter shooting the C300 still owns the market segment and there are very good reasons why it does. The image is beautiful and really easy to post with and requires low end hardware and not much support to use. Great single operator camera, I see them all over. Canon is a lot like Apple: poor specs for the money, but great user experience and system loyalty for that reason. Arri even more so. The highest end cinema camera still has the lowest resolution sensor, but the Alexa is a dream. Curiously, Canon's lowest sensor density camera is also its most professional, the 1DX. Nikon's D4 is even lower-res.... Maybe not so curious. Pros pay for hard drives, they don't sell more photos if they have more resolution beyond the baseline needed.
Black Magic seems cool, but I find their products horribly bad for ergonomics, and the 4k has static noise like crazy and just a bad interface whereas the 2.5k aliases like nuts and also has a bad interface. The pocket camera seems cute, though incomplete. Cool studio camera for well-lit green screen shots, but not as flexible by any means as any of the competition.
But yes, Canon did abandon anyone who wants "cinema" video IQ in a dSLR for cheap (whereas Sony and Panasonic made some great strides here), and they did so to support their cinema line. The Mark III isn't terrible and the 70D introduced really cool AF, but the image didn't get dramatically better. No, it wasn't very nice for them to focus on professional gear instead, but so far it has paid off financially. To be honest, I also think the C300 is a great product, just pricy. Sharpest 1080p on the market (sharper than some 4k and probably as sharp as the Alexa's 2k tbh definitely sharper than Alexa 1080p), great colors, easy codec to handle in post. I still hope the C300 Mk II is strong enough that Canon isn't afraid to improve their image quality on their still cameras. The 5D Mark II still has a nice look, and Canon does great color processing. Would be cool if they improved the specs just a bit, I agree, but they will never again be cutting-edge, at least not intentionally. The 5D Mark II was a fluke. Also, 120fps... that would be sick.