First:
That's not really the point whether this camera is for me or not. I do a lot of stills work as well, so the R5 (once it arrives next week) will find some place in my kit and will easily replace the 5D4. It will play nicely alongside the 1DX2.
Second:
The real question is "does it have to be that way", or can Canon fix it with better power management, slightly less conservative heat limits (within safety of course) or a hardware fix getting the heat away faster. Can they make usage of the fancy, advertised video modes be less clunky. I don't think any other camera on the market locks you out of the "premium" features for hours once it gets too warm.
Thanks to people drawing attention to these limitations, whether you think it's overblown or not, there is a small chance Canon will actually be "forced" to make the camera better. And each of the things I listed above will improve photo mode as well.
power management: more battery life
heat limits: it will not start to throttle shooting speed. Yes, temperature is a factor in that, as per the manual.
heat dissipation: less heat means less sensor noise
So instead of just repeating "it is what it is, deal with it, this camera is not for you or for serious video shooters, get a Cine Camera", think about why this has to be a Canon-god-given fact when other manufacturers can just do better in this regard.

From the CR Guy backchatter it seems they're at least looking into it. So what's the problem with that, I'm glad if they do.